So this is 'gasoline' diesel. Or diesel without the NOx. Which, in theory, would give better fuel economy and possibly better torque. And it will ship in cars in the 2019 model year (so possibly as early as late next year).
To me, it sounds like a "Don't pass"[1] bet on electric cars. Which they also are working with Toyota on electric cars so perhaps it is a fall back plan. It will be interesting to see how it fares. There are a lot of products that are built as the other side of an industry change bet. Sun created a workstation on the 68040 in case the SPARCStation didn't meet expectations as an example.
[1] In the dice game Craps, the "Don't Pass" bet is against the current player 'winning.'
Gasoline engines aren't going away for a while; even when every self-driving car is electric, there will be a market for people who want gasoline engines. If it gives a bump in fuel economy to the next (last?) generation of gasoline and hybrid vehicles, great!
I also wonder if the maintainability of these engines will be the same as with diesel. That would be another big benefit.
I visited a Tesla store once in mountain view, and they have a great little demo where you can check the cost of charging your car in various states.
Washington DC, for whatever reason, gets its electricity from a gasoline power plant. In Washington, the Model S gets 28 MPG.
This happened a while ago so I could be misremembering, but regardless I don't believe that the environmental value of electric vehicles has been realized. In a lot of places, your Tesla is still coal powered. Efficient internal combustion engines are still a worthy cause, and this will continue until more electricity is being produced than is normally consumed.
Electric cars are the real world example of loose coupling. Once your car is electric the source of the electricity can change (from Coal -> Gas -> Solar) and you don't have to change your car even slightly.
So it doesn't matter about any of the arguments about whether an electric car is more efficient or not when the electricity comes from coal.
What matters is that having electric cars enables us to move to a future of solar and wind and not notice the difference.
Plus having electric cars that don't pollute in cities where there are lots of people and generating the electricity with coal fired powerstations outside of cities where there are less people has immediate benefits.
> Plus having electric cars that don't pollute in cities where there are lots of people and generating the electricity with coal fired powerstations outside of cities where there are less people has immediate benefits.
While this is true, much as the rest of your comment, this sentence has made me think that pushing pollution away from the eyes of people is a really negative effect of electric cars. If pollution is not in my backyard, I'll certainly be less aware of it, and hence I'll certainly pressure less for reduction.
I kind of hope not. As bgarbiak points out [0], there's other things that we start talking about once the pollution of fossil fuels is out the way.
Also once people have electric cars the incentive to have solar panels on your roof becomes bigger. Then once enough electricity is generated through that the coal power stations just get turned off because they're not needed.
Plus there will still be the issue of CO2 generation, just that drivers won't be responsible any so like ex-smokers (who in my experience seem to be more anti-smoking than most) they'll probably be even more offended by the polluting power stations.
I'm as big fan of EVs as the next guy, and would love to see cities with clean air and no noise. But, there are few things that we forget about when we talk about zero-emmision cars.
EVs pollute less, but they pollute too, and in cities as well. They emit dust (including the most harmful particles: PM10 and PM2.5) from break discs and tires.
Difference between CO2 in power plants and in city centers matters, but not that much. Once it's in the atmosphere the damage is done. As for NOx, the biggest offender in the dieselgate, Mazda's engines should not emit these.
Add a fact that in the current grid setup most of the energy is coming from coal, and that it's very unlikely it is going to change in a near future (mainly due to political reasons). Also, the waste from batteries is really ugly.
Given all that factors a 30% less polluting combustion engine is almost too good to be true. From a macro perspective the gain for environment is on par, if not better, than from electric cars.
My biggest problem is to believe in the numbers Mazda provides. Have to wait and see.
My main point was the loose coupling and getting off the hook from fossil fuels.
I shouldn't have made the point about city pollution as it just diluted the main point.
Nevertheless, the brake discs won't be any worse in electric cars, so it is an absolute reduction in pollution in cities. I've also only heard such things getting raise ever since we started talking about electric cars. When everyone is worring about NOx we forget about all the other polluting steps.
Coal power stations are the worst case scenario for electric cars and even with this things are on a par. But back on my main point with electric cars we can switch to Gas fired power stations and then to our own solar powered roof. With a Mazda ICE you're stuck on petrol.
Plus petrol in the long term can only get more expensive and solar can only get cheaper. Petrol is eventually going to run out and before that happens it's going to get very expensive. Solar panels and batteries will only get more efficient and cheaper to produce.
Battery recycling is definitely an issue and Elon Musk has quoted at the gigafactory opening that they can take all Tesla batteries back an recycle them fairly efficiently as their robots can strip the batteries apart as they have the schemas. Whether other car manufacturers follow suit is open to question.
As far as political reasons go, if everyone is driving electric cars I'm sure there will be much more political pressure to remove the polluting power stations because now CO2 is primarily the fault of the power stations rather than people driving around in their cars.
> From a macro perspective the gain for environment is on par, if not better, than from electric cars.
Citation needed. It seems obvious to me that a huge power plant is going to be less polluting per kWh than a tiny little engine in a car. Otherwise, we'd use tiny little car engines to power everything - which only happens at the moment in places where they cannot get electricity by other means (building sites etc).
However, I have to agree that my previous comment _wrongly_ implied that burning coal at the plants to power the electric cars is the main issue we have to deal with.
Don't forget that electrical grid transmission losses cause massive efficiency problems before centrally generated power ever reaches that car charging point -- on the order of 30% or more, and conversion from AC to DC at the charging port may account for another 10-30%. (Made up numbers, but they're in well within range IIRC)
I don't think it follows that just because we have historically centralized power generation, this was obviously due to efficiency. For example, centralization of management, investment, pollution control, logistical (fuel delivery), safety (nuclear) and reliability concerns seem far more obvious to me, although I don't doubt there could be an efficiency benefit to large-scale generation, I've just never heard of it.
> conversion from AC to DC at the charging port may account for another 10-30%
Simple rectification has not so much loss, I think you are thinking about low voltage DC power supplies, and I think that chargers for large, high voltage battery piles are likely to be happy with rectified (maybe doubled) mains supply.
The low voltage supply is first rectifying the input, then using an inverter to generate high frequency AC, then rectifying and filtering this to give a DC output.
The simple "diode" rectification is no longer acceptable due to harmonics put on the AC side causing grid stability problems and emitted radio interference.
> Add a fact that in the current grid setup most of the energy is coming from coal
Coal represents less than a third of North American power generation, and less than a quarter of generation in Europe. In Brazil (another major car owning country) coal only represents ~1% of their generation sources.
Really the only place your statement is true is mainland Asia, and even there the market share of coal is falling (and the number of cars there is dwarfed by the number in NA/Europe/Brazil).
The biggest nail in the coffin of the long tailpipe fallacy is that you can drive an EV farther on the power needed to refine a gallon of gas than you can drive a ICE car on that same gallon. So, even if you built a gasoline engine that had absolutely no emissions, and oil bubbled up into crude lakes right next to every refinery, EVs would still be more efficient.
This means there was 4.8 MJ of energy spent to create 1L of gasoline. The 70kWh(250MJ) tesla is reported to have 390KM range. 4.8 MJ would be 1.92% of the range, or about 7.5km. The Mazda 3 has a combined fuel economy rating of 33 MPG, which is about 14KPL.
As far s I can tell, your statement that an EV can go further on the power needed to refine a gallon of gas, than an ICE car can drive is off by a factor of almost two.
That said, arguing an electric car can go a certain distance based on inefficiencies of another unrelated process is not a very meaningful argument. You need to look at the efficiencies and CO2 produced for drilling/transporting/refining/burning gas vs producing/transmitting/storing/using electric power, and probably the costs of dealing with peak loads vs non-peak loads, and even then the argument is heavily weighted on where your power comes from.
Well, the US average for fuel efficiency is 25, not 33. And the Model S is one of the least efficient EVs, for worse than the average. Adjust both those numbers in the right directions and your math lines up with my point nicely.
> This happened a while ago so I could be misremembering, but regardless I don't believe that the environmental value of electric vehicles has been realized
Indeed.
However, look at it this way: which is easier to replace, the entire fleet, or centralized power plants?
Every time a new windmill or solar panel is added, your Tesla gets that much cleaner. And that's something you can do yourself if you want to. Electricity is fungible and your car could not care less where it came from.
Oil changes have a non-negligible impact for the environment as well. And then there are all those components that have to be replaced from time to time and end up in landfills (spark plugs/cables, timing belts, etc).
So I believe electric cars today are already a net gain. And, even if they polluted more, the pollution is centralized in the power plants, which is easier to do something about. There are problem health benefits from moving pollution away from population centers.
I make a point of going to parks with my EV. I know it's a token gesture, but I like to think I'm not blowing dirty fumes next to animal habitats. It helps that California is reasonably clean.
> However, look at it this way: which is easier to replace, the entire fleet, or centralized power plants?
The entire fleet I'd think. It's certainly much more likely to happen first.
(Cars have a much shorter average lifespan than power plants; the natural gas power plants we're building right now have a designed lifespan of up to 50 years. Very few cars coming of the production line today will be on the road in 50 years.)
That is wrong. Almost all of the energy DC uses comes from its interconnect to the RFC grid. Locally, it does look like 2/3rd of the power DC generates is nat gas, and 1/3rd gas or gas-like, but it doesn't make sense in a grid structure to assume that the energy produced near you is the energy you use.
Given that its neighbors' top two electricity sources seem to be Nat Gas and Nuclear, seems probable that most of the electricity comes from those sources
You should really just take a weighted average of all the things putting energy onto the eastern interconnect grid(including grid-tied home solar installations, but those are probably negligible in the grand scheme of things at this point).
The reality is that anyone in the US, east of the rockies and not in texas will have the same 'mpg equivalent' for their Tesla.
What they should be doing is showing changes to range and costs throughout the year. During mild to warm months my EV range on a Volt is much better but come winter. Same goes for pure EVs. Pure EVs are not truly viable even with the Tesla network for long trips, once past a two charge trip you timing has to be truly altered and it gets worse in hilly country or winter.
Now in winter gasoline/diesel cars have the issue of nearly always running rich on very short commutes as they strive to get to an optimal operating temperature. The EV just loses a serious chunk of range. Both of course can be preconditioned but the EV is more efficient there.
As for Mazda. None of the electrification upcoming laws exclude fuel powered vehicles, range extenders and hybrids all seem to meet many requirements.
I think the long-trip problem is solved by families owning one gas or hybrid car, and one pure EV car. Or even two pure EVs, and planning to rent a gas powered car for long trips!
Agreed, but there is also incentive to install solar panels on your home/garage to charge your car. Too bad most of us are at work (car out of garage) during peak sun hours, so it gets more complicated. Maybe this is the reason Tesla also wants to sell a 10 kWh battery along with a solar roof.
Diesels aren't inherently more maintainable than gasoline engines. That impression comes from the fact that diesel engines are used in situations where durability is paramount, thus are designed to be robust. Most passenger car engines have several criteria that are more important than maintainability (emissions, power, fuel economy, size, cost, manufacturing simplicity).
People don't hold up BMW passenger diesels as the hallmark of maintainability. Heck, even the diesel offerings in American trucks are pretty bad from a reliability standpoint. Both Cummins and Navistar faced multiple CALs over reliability and warranty-related issues.
Here where I live, modern turbo-diesels are considered less reliable than NA gasoline engines. They are much more complex and need fragile components like DPF filters and turbocharger to get acceleration on par with low-torque, high-RPM gasoline engines.
> I also wonder if the maintainability of these engines will be the same as with diesel
They also include traditional spark plugs and the engine automatically switches between modes. So, I fear that maintenance wise, it may be the worst of both worlds -- but with less wear and tear on the spark side, perhaps it will be better.
I'm pretty sure "wear on the spark side" is an all but solved problem at this point. Most car engines made in the last 15 years have 100k mile lifetime on the entire spark system.
I know for more recent vehicles that is probably true, but as an owner of a 2006 F-150 with the 5.4L 3V Triton V8 that had the infamous spark plug issue, I had to lol with a tinge of sadness at your "last 15 years" comment.
Backstory: Ford came out the gate with a new spark plug design for the 2004 F-150 3V Triton 5.4L V8 engine (after their previous spark plug design failure in the 2V Triton where the plugs would shoot out) and told everyone that the spark plugs would last 100k miles. Turns out if you let them go that long, they would get stuck in the cylinder head and break off when you tried to remove them, leaving stuck broken pieces of spark plug behind. Conveniently, 100k miles happens to be when most people's warranty expires, leaving people with a best case a few-hundred-dollars-extra tune-up bill, if not thousands of dollars if the heads had to be removed. Ford faced a class-action lawsuit over this debacle, and there are still companies selling special broken spark plug removal kits designed solely for this engine to this day. Of course the root cause of the problem is faulty design, but it would have been mostly avoided had they not claimed a 100k mile service interval for the plugs. So yes, Ford went from an engine where the spark plugs would shoot out of the cylinder head, to one where they would get stuck so hard they would break.
I know all of this not because I am an engine geek, but because it happened to me. Two spark plugs broke off while being removed and I came this close to needing to have the heads removed and machined. Fortunately those special removal kits I mentioned earlier really do work. Given how relatively cheap spark plugs are, you can bet it will be a while before I trust that 100k mile number :-)
Well, that's sure unfortunate. I care for my father in law's focus, and the iridium plugs really were good for 100k miles. In 35 years of caring for cars I have never been so frightened by the sounds and feel of unscrewing a spark plug though.
This is the one with a "permanent air filter" so they were thinking about eliminating maintenance. Boy this is going to suck when it is clogged.
I agree that for the most part engines are extremely reliable. The potential downside here is that the compression mode makes the entire system more complicated. This might make the new system less reliable. I have every confidence that Mazda will do this right, and this has great potential to extend the lifetime of the ICE. However, it isn't without risks.
Outside of Europe maybe. Inside, well, UK and France have already said no more ICE vehicles to be sold past 2040, and other countries are planning the similar (including India). That’s a big loss of market and consequent economy of scale.
When your country has only 5 million people and is a top petroleum extractor and exporter, sure, it's easy to subsidize electric vehicles. Realistically it should be 2020.
> To me, it sounds like a "Don't pass"[1] bet on electric cars. Which they also are working with Toyota on electric cars so perhaps it is a fall back plan
The Toyota/Mazda collaboration is a pure compliance play, just like what Honda has done in California for years (read: Honda Fit EV.) The official announcement had a subtle hint:
From 2019, start introducing electric vehicles and other electric drive
technologies in regions that use a high ratio of clean energy for power
generation or restrict certain vehicles to reduce air pollution
as The Verge clarified it in more details here[1], Mazda have to sell EV in regions where regulations are so tough that they can improve the efficiency to pass or in regions where ICE cars are/will be banned altogether.
Also the new Toyota/Mazda auto plant is not going to manufacture only EVs but also other ICE (Internal Combustion Engine) cars.
And yes, without their own EV or the resolve to electrify their model lineups, Mazda might not even survive after 2025 when they plan to use SKYACTIV-X on all of their cars.
For EV, the old saying is true: driving is believing.
Took my car for service to a mixed Nissan/Mazda dealership here in Norway. All salespeople were busy working on Nissan side selling Leafs and electric vans..
I believe it's a "luxury/enthusiast" strategy.
I believe the auto market will play out something like the watch market did with the introduction of the quartz watch. Most people just want to tell the time, so they buy a quartZ. Similarly most people just want to get from A to B, so will buy an electric (automated) car.
Some people enjoy the mechanics of the thing. So they buy a nice mechanical watch. These watches went from being simple utility pieces to works of art.
Similarly I expect that car companies will continue to sell a set of "enthusiasts" models for a long time. They might revert back to manual gearboxes, and become more and more outrageous works of art - turned polished engine bays (Think Perlée, etc).
When all your actual needs can be met by a self driving electric car, why do you own a physical mechanical car? For the enjoyment of it.
Of currently available models, isn't that essentially ... one of them? And only in a straight line. Electrics have a ways to go before they're suitable candidates for things like track days.
Arguably the Model 3 isn't "currently available" but Motor Trend is a big fan for more than straight lines:
"The Model 3 is so unexpected scalpel-like, I’m sputtering for adjectives. The steering ratio is quick, the effort is light (for me), but there’s enough light tremble against your fingers to hear the cornering negotiations between Stunt Road and these 235/40R19 tires (Continental ProContact RX m+s’s). And to mention body roll is to have already said too much about it."
Perhaps, but I wonder if we won't see more countries go the way of Norway/France/Britain and ban gasoline cars altogether once electric vehicles become more competitive and mainstream....
Sweeden and Norway, where battery performance is impaired by the colder climate. The next absurd thing would be Alaska announcing a ban of ICE vehicles after 2030.
I drive an EV in Norway for soon 4 years, there is no performance impact whatsoever. Sure you use salon heater way more, but battery capacity hardly budges.
Winters are pretty mild throughout more populated parts of Norway and Sweden.
I don't quite like the fact that the spark plug is burried deep inside the engine which makes servicing difficult. Reminds me of Porsche boxer spark plug changes for which you need to unmount the rear wheels.
Sounds interesting. I'm very curious, though, to see an ignition profile of the compression ignition concept: it seems to me that compression would be even throughout the ignition chamber, leading to a somewhat (within the bounds of statistical deviation in fuel/air pressure) simultaneous ignition of the fuel/air mix. Meaning that I think Mazda's technology would combust more efficiently.
Thermal efficiency basically refers to just the efficiency of an ICE (or any heat engine for that matter) – i.e. how much of the chemical energy of the fuel you manage to convert into mechanical energy in the drive train. The better the efficiency, the less fuel you need to produce the same power output, obviously producing less CO2 in the process.
(To be more specific, the terms are often used interchangeably. Thermal efficiency has an exact definition in an ideal heat engine and even ways of calculating the theoretical maximum for given conditions – but CO2 or chemical reactions have nothing to do with an ideal heat engine to start with. I'd personally perhaps prefer to talk about just the efficiency in an actual ICE – even if just to be clear none of the losses are conveniently left outside the calculation.)
NOx is not peculiar to diesel engines. Gasoline engines also generate NOx. All internal engines make NOx. As long as you burn fuel + atmospheric air you get NOx. The atmosphere is 78% nitrogen. Some of it gets oxidized.
This makes me wonder whether it would be theoretically possible to use some of the engine's power output to extract nitrogen from the incoming air. You'd effectively be trading more CO2 pollution (because of the reduced efficiency) for less NOx pollution.
My back-of-the-envelope calculations suggest that off-the-shelf oxygen concentrators aren't efficient enough to make this practical, but I don't know whether there are fundamental thermodynamic limits that would prevent the efficiency from being improved.
The catalytic converter helps to manage this in a gasoline engine. Cats are more difficult for diesel, which led to the ammonia fluids that current diesels use to minimize NOx emissions.
I don't understand why not simply cool the exhaust gasses down with a big heat exchanger enough to condense the water vapour. That water would then react with the NOx to form dilute nitric acid, dilute enough to just drip onto the road with little environmental harm.
The same condensation process would also trap all the carbon particulates.
Most gasoline engines are homegenous charge, and run within a few percent of the stoichiometric air fuel ratio. Diesels will run at 6x the stoichiometric ideal amount of air.
Or a bet on hybrids. Hybrids enable new types of engines that for instance operate at constant rate or that are under-powered for acceleration from a stop or going uphill.
I bet on plugin hybrids, specifically ones with large batteries. This seems to be an unpopular opinion, but I think the Voltec drivetrain shows what's possible here. Pure EV purists dislike PHEVs because they have the complexity of an ICE car + an EV car, but I think there's some serious advantages. Like you say, Atkinson cycle for electricity generation for when the battery drains beyond smaller commute ranges. Something like this new Mazda engine in that context would make quite a bit of sense for overall fuel efficiency.
> because they have the complexity of an ICE car + an EV car,
The irony being that most don't. For example, hybrid synergy drive is basically an alternate transmission design that replaces the complex clutch packs used to control Ravigneaux planetary gears with electric motors. The result is a more simple overall design.
Other systems are literally just beefed up starters.
I agree. The Volt to me is a beautiful piece of engineering, and the ICE system is actually simpler than a regular ICE car _because_ of the presence of the EV side of the car, which compliments it.
I think it's more of a political thing -- if you've made the argument that "ICE = pollution = bad" then it's hard to turn around and say "but a little bit of ICE to extend range is good."
The battery + electric motor adds so much good -- regenerative braking, electric torque, good city driving experience, it really feels like every car that is now an ICE should be a hybrid, even if just a "soft" hybrid with no plug, like a Prius.
> Pure EV purists dislike PHEVs because they have the complexity of an ICE car + an EV car, but I think there's some serious advantages.
I would imagine most the complaints are for when the ICE actually powers a drivetrain. If it's essentially a generator to keep the batteries from depleting too far, that's not much extra complexity it all. Have a problem with the generator? Just swap it out with a new or rebuilt one from some vendor (if designed well such that you can do so). I'm seeing that a Tesla uses about 300 Watts a mile @ 55 Mph.[1] Honda seems to have generators much more than capable of supplying that need for under $1000.[2] I'm not familiar enough with electric systems to know how accurate that assessment is (whether the voltage requirements complicate it, for example), but that seems promising. Then again, I imagine if it was really that easy, Tesla would have put a generator charge hookup and exhaust ventilation capabilities in the trunk already.
Edit: Hmm, I'm definitely missing something, since the $1000 generator says it can go 8.1 hours on a gallon of gas, and it doesn't seem likely for that to translate into powering a Tesla for 8 hours of travel.
This is nonsense. The dimensions are wrong. Watts are instantaneous power. To be meaningful, you would have to give either kWh/h or kWh per mile or km.
Besides that 300 W is only 0.4 hp. Sorry, but that is just not credible.
Not to dispute your claim that it's low, but the physics checks out.
The cited link saves me explaining it:
>Reports are 300 W/mile at 55 mph. If you do the product of these two numbers (300 * 55) all units but W will cancell eachother out so the answer is 16500 W = 16.5kW
The time component being on the mph allows the conversion.
No. 300 Watts / mile * 55 mile / hour leaves you with 16500 Watts / hour, which is a non-sensical unit.
On the other hand, using the correct units (300Wh/mile):
300 Watt * hour / mile * 55 mile / hour = 16500 Watts [a sensible unit] (or about 22 horsepower which is reasonable for a steady 55mph cruise).
Do that for an hour, and you get 16.5kWh of energy consumption and cover 55 miles, for an energy efficiency of 3.33 miles/kWh, which is in the ballpark (albeit low) for what my LEAF delivers (averaging a bit over 4 miles/kWh at average speeds somewhat lower than 55 mph)
Yeah. I expect the unit being used is 300 Watt-hours. IOW: (300 Wh/mi 55mi/h) =16500 W, or 16.5 kW. Which actually sounds about reasonable, being 22 horsepower.
From what I read about HCCI engines (the brand-neutral name for the general engine concept: https://en.wikipedia.org/wiki/Homogeneous_charge_compression... ) I suspect that they are not easily operated over a power band as wide as conventional gasoline or diesel engines. If that is the tradeoff, they could be a perfect match for hybrids.
I don't think hybrids have any future except in the heaviest of vehicles, where batteries won't make sense for another few decades.
We're already seeing companies being interested in making battery-only buses, tractors, semis, and even airplanes. Not all models of those types of vehicles may work with batteries, but it's a sign of what the future could bring.
Total individual perspective here, but my dad took me on his worksite like 15 years ago to see the big super gorram awesome trucks (seriously those things are HUGE). When I asked about the engines, he said the trucks had massive diesel generators that powered motors, that in turn powered the wheels and hydraulics. So in a way, lots of construction equipment has kind of already been "hybrid."
An electric power transmission is hardly hybrid. You just have two extra conversions in your transmission, mechanical to electric and electric back to mechanical.
The diesel-electric system used in Locomotives and heavy off-road mining trucks are literally examples of series hybrids. You may be objecting to ththe lack of battery storage, which isn't useful in those applications.
battery only buses make sense because the bug needs to run over rush hour and then can sit all do to charge. Battery operated tractors do not make sense without vastly better batteries because a tractor needs to run for 16 hours at max power (500hp). Sustaining 400000 kw for 16 hours is not easy. For semis and airplanes you need to consider your use: for short in town loads/short flights batteries can work, for longer distances we don't have the battery technology today to make it work.
Someone once told me battery technology has 2-3 more doubling left and then we hit chemical limits and cannot get more out of them. If this is correct batteries can never do the longer distances, but I don't know if it is correct.
> battery technology has 2-3 more doubling left and then we hit chemical limits and cannot get more out of them
We still have energy cells which are essentially bateries that you charge by pouring in some fluids just like in a regular car. However the tech is not mature enough yet.
While I don't believe hybrids will survive in the long run, I think that hybrids (and plug-in hybrids specifically) will play important role in transition period of passenger cars (use EV in cities, use gasoline if you want to go >100 km, refuel whenever you want).
A have Toyota Auris with hybrid synergy drive and even though it has really small battery (so it costs less than $25000 including tax), I am able to ride through small town using EV mode only and then use ICE between towns. My mileage is 4.4 l/100 km which is ~53.5 miles per gallon and I'm driving in city most of the time.
I considered i-eloop when it came out for its first generation, in the 2014 Mazda 3. It was estimated to bump my city MPG by 1. And was only available in a very expensive package. I passed.
In the linked page they say they're pursuing both internal combustion and electric vehicles and they explain their rationale:
- In line with this policy, continue efforts to perfect the internal combustion engine, which will help power the majority of cars worldwide for many years to come and can therefore make the greatest contribution to reducing carbon dioxide emissions, and combine the results with effective electrification technologies
- From 2019, start introducing electric vehicles and other electric drive technologies in regions that use a high ratio of clean energy for power generation or restrict certain vehicles to reduce air pollution
Mazda is only working with Toyota on electric because they have to for compliance reasons in CAFE states. The CEO has quite recently panned EVs and said they will die when subsidies go away[1]. I'm sure they will produce a compliance-only vehicle available only in California and probably only for lease, like Honda has done with the clarity.
I don't necessarily see this as a don't pass. There are some questions to the jerkiness of the power supplied, so perhaps this kind of engine would couple nicely in a hybrid design - it can charge the batteries 30% more efficiently than the closest hybrid, and the user isn't getting power to the drivetrain directly from the engine, eliminating any jerkiness.
LANL published a paper circa 2007 or 2008 on how to make carbon-neutral hdyrocarbon fuel using carbon in the air and the electricity and waste heat from a nuclear plant. According to the paper, it was competitive with oil-based gasoline at around $5/gallon.
Its authors badly underestimated how much new American nuclear reactors would cost.
We performed economic analyses on a partially optimized baseline concept based on a single Gen III PWR to provide power for the process. The analyses estimated a capital cost of $5.0 billion for an 18,400 bbl/day synthetic-gasoline plant and $4.6 billion for a 5,000 tonne/day methanol plant. Nuclear power accounts for more than 50% of the total plant capital investment.
If just over 50% of that cost is supposed to be nuclear plant, it would be $2.5 billion for a Gen III pressurized water reactor. ($2.9 billion now, accounting for a decade of inflation.) The just-abandoned VC Summer project was supposed to build two new Gen III PWRs in South Carolina. They pulled the plug because estimated cost of completion had spiraled up to $25 billion ($12.5 billion per reactor).
You don't need gasoline. The gasoline ICEs can run on ethanol and LPG and diesels can run on DME (dimethyl ether) and vegetable oils. DME can be produced using nuclear process heat and/or hydrogen or using biomass.
it is called battery charging :). Basically it is making the fuel - Li - out of the ash - lithium oxide. The amount of Li and available for "burning" oxygen in the current batteries is very small and where is no principal reasons it can't be increased 10-fold to something like 10% by weight (especially in the metal-air schemes) at which moment it will leave gasoline engines well behind in all respects.
>Compression ignition and a supercharger fitted to improve fuel economy together deliver unprecedented engine response and increase torque 10-30 percent over the current SKYACTIV-G gasoline engine.*3
Wow. I already have a 2016 Mazda 3 that gets around 40MPG (even though it's not a hybrid) and it's already pretty peppy.
Probably the best car I've owned, and I've owned several nice sports sedans. Getting 40MPG is too convenient when you make longer commutes, not to mention the thing cost ~20k at 0% APR. Blows any hybrid out of the water for total COO.
Agree, these are awesome cars. I have the 2014 Mazda 3 2.5l (SkyActiv) Astina, in a manual sedan. I do lots of commuting peak hour traffic, so my economy is seriously affected - I get about 9l / 100km on those days. On a proper open highway 100-110km/h drive I'll be on around 5-6l / 100km however.
Acceleration is very zippy indeed, and the manual whilst not inviting the most efficient driving is an easy changing, short throw type. Tech level in the car is amazing: Radar cruise, AEB, blind spot monitoring, rear cross alert, Adaptive Front Lights (inside lights looks into the corner), etc etc.
It's very exciting to see normal petrol engines becoming so much efficient. Kudos to Mazda here. I'm hoping they'll have a hybrid or even all electric out by the time it's time for me to upgrade the current one.
OK, so honest question: I have a 2012 Mazda 3 which, presumably, gets 40mpg. But I can't realistically get anything above 29mpg on average. Am I just an aggressive driver? :)
[edit] I agree, by the way, that the cars are incredibly fun to drive, for being "fuel efficient."
If you don't spend 95% of your time on a freeway, you'll never get close to the top MPG. This is how people like to compare their cars to hybrids: their car's highway MPG to a hybrid car's combined. Problem is, the hybrid probably doubles the their MPG in the city. But, if you're a long-range commuter, I guess that doesn't matter much.
I have a 2012 Mazda3 sedan with the 2.0L Skyactiv-G engine. I drive a daily commute on a 50-50 highway/stop-n-go mix. My average mpg has consistently been 35 mpg (40 highway, 32 off). The hatchback has slightly worse mpg, so does the manual transmission, but 29 mpg sounds more like the non-skyactiv 2.0L engine. The 2.5L sport engine would be closer to 25 mpg.
I'd check under the hood just to make sure :) then fill up the tires, reset the average fuel economy, and baby it on the highway to see if you can get around the expected 40 mpg.
2012 had half Skyactiv and half .. non-Skyactiv. The expected MPG on the non is around 30. You'd have a badge on the rear of the car (if sold in US, at least) that would indicate Skyactiv.
I had the 2012 for a few years. When I was driving 80%+ highway, I would struggle to get below 35MPG or above 42MPG.
On a 50%-50% split, I would be in the mid 30s, usually 36MPG or 37MPG.
When I was 80% city, I would be around 32MPG on average.
That car does not have much low-end torque, so if you accelerate aggressively from stops you can definitely tank the MPG. I didn't see much impact from aggressive acceleration at highway speeds (e.g. going from 30MPH to 70MPH on an on-ramp, or pulling around a slow group of cars going from 45MPH-70+MPH). I did see a lot of impact from flooring it 0-30.
The correlation between efficient driving and aggressive driving is far from perfect. The "pulse and glide" method from the wikipedia page linked in a sibling comment would seem quite aggressive for example and on the other end of the scale, I have often seen "moving roadblocks" running their engine at RPM far too high for efficient cruising (e.g. when people drive a manual who are afraid of shifting).
Hauling ass from one light to barely run a red on the next one is a hell of a lot more efficient than seeing the yellow, accelerating like an old man, coasting for awhile, braking to a stop and idling for several minutes.
Every time you touch your brakes you're throwing away the energy it took to get to that speed. Coasting through off ramps at highway speed is good for the environment.
> Blows any hybrid out of the water for total COO.
Not so sure about this. I have a 2014 3i GT and my wife has a 2014 Prius. Hers was cheaper to buy, gets way better mileage (29 v. 44) and needs less frequent oil changes (which are free), and is worth about $1200 more now.
It's a little faster, nicer inside, and much more fun to drive. But cheaper, nah.
I'd assume the parent comment is referring to the base package version of the Mazda 3. I was able to get a 2015 Mazda3 S Touring for ~$25k with all taxes and fees included, so I think $20k is a fair estimate if you assume the base package
Indeed. I was shopping recently and the 2017 Sport was going for under $18k with current Mazda incentives ($2k cash.)
(I ended up with a 2015 S GT for $20k - only 8k miles on the odometer :)!)
Also - that's an i (2.0L) which gets 30/40 mpg (about 34-35 overall) so not quite the stark difference in fuel economy compared to a Prius that the 2.5L has.
(gallons per 100 mile difference between 35 mpg and 44 mpg is 2.86 vs 2.27)
Torque is directly proportional to power, related by angular velocity. So τ Nm of torque at angular velocity ω rad/s will give you power P = τ·ω in watts. In fact this works for three-dimensional τ and ω if · is the scalar product.
Oh and an RPM of N is equivalent to angular velocity ω = N·π/30.
I only wish you could get the 2.5L in a manual with no moonroof. That would probably get me to buy a new car.
I have an 07 Mazdaspeed3 that is getting long-in-the-tooth, and it gets terrible mileage (19 in town, high 20s on the freeway). The best I can say about the shifter is that you get used to it.
I don't think I need quite as much pep as my current car (plus all current hatchbacks that are comparable performance are north of $30k), and the 2.5L engine in the Mazda3 is nice.
I like the Mazda3 better than the Focus, but if I had to get a car today it would probably be the Focus ST.
For what it's worth, I went from a WRX to a 2L 3i and don't miss the extra horsepower because we felt, frankly, that they're all slow, so why pay a premium for slightly less slow? With that said, it's plenty fast enough for city driving and is the most fun FWD drive car I've driven, bar none. Hell, it's the best car I've owned and only barely not the most fun (after my RX-7). The interior is great, it's cheap to run, ...
Oh, parts of PA are quite bad, though it's been a while since I drove there. Come to Southern California where there are all sorts of on/off ramps that are only on a single side of the freeway and have 90-degree turns followed by essentially zero merge area onto a 65MPH speedlimit.
loved my 6-speed 2015 mazda 6. highway miles were truly amazing for a full sized sedan. like others said i'm glad to see mazda continuously innovating. it's paying off
Your Astra weighed 1000lbs less, had no air conditioning and probably no air bags and would have probably killed you in a 40mph collision though, innit?
And that mileage was presumably measured using imperial gallons, which are 20% larger than US gallons. And it probably didn't get 40mpg anyway unless it was on the highway 100% of the time.
Any chance your MPG was measured on imperial gallons? Looks like 40MPG imperial would be normal for that car, but 40MPG US would be a fair bit more than expected.
Modern small cars with small engines can be quite fuel efficient in highway driving, though, and there 40 mpg isn't quite the very top. A month ago or so I did a trip in a 2016 Seat Toledo (petrol, non-hybrid), and the drive computer reported the consumption as 3.9 L/100 km after 150 km of driving at speeds from 60 to 100 km/h, averaging IIRC 78 km/h.
A 80 km strip at 120 km/h increased the average to 4.2 L/100 km.
Mercedes Benz introduced something very similar to this ten years ago[1]. The engine was using HCCI at low RPM and conventional spark-plug ignition at higher RPM.
That was purely experimental though - Mazda's is going on sale to the public which indicates that this is a much more evolved product.
Whilst most other manufacturers have persued downsizing and turbos to get efficciency on paper (at the expense of real world emmissions) Mazda have gone another road with their SkyActiv technology and it seems to be paying off for them.
Rotary is actually a good example for "revolutions" that turned out to be inferior compared to existing solutions. We will see how the new engine will perform in the real world.
Wankel engines work fairly well, but the geometry is so constraining that they can't be improved much. Can't change the shape of the cylinder head. Can't change the valve timing dynamically. That's all fixed by the geometry. They got as good as they were going to get decades ago.
Wankels are cool but they really don't have an advantage over regular engines other than vibrating less as far I know. And they have a few distinct disadvantages.
Better power curves & higher RPM capability, so you can use a smaller, more underpowered engine for the same application.
But that never overcame their mediocre gas mileage (lack of compression/poor combustion chamber shape), oil burning (oil-lubricated apex seals), and need for frequent rebuilds.
The rotaries leaked oil and got terrible mileage, and good luck finding someone to work on them. Other than that, they were zippy. "Usable" they might have been if you keep a low bar, but "practical" they were not.
I've had Mazda's last model of rotary-engined car, the RX-8, as a daily driver for the past five years (sixty thousand miles). It has served me well and my local garage have performed regular servicing and mechanical repairs with no problems.
So I think your opinions are a little bit overcooked.
But I don't want to overdo mine in turn. The fuel consumption is excessive by modern standards (but comparable to other vehicles of similar performance). The engine consumes oil by design and needs to be topped up every few weeks. The whole car is in a high state of tuning, and has given me a few large service/repair bills - but never stranded me at the roadside. My garage once admitted incomprehension and sent me to the main dealer for diagnostics before they could begin repairs.
All in all I think Mazda pitched the RX-8 well as a sporty car for enthusiasts, whose reliability might have come in under par in the market for, say, small family cars. I just want to fight the impression that having a rotary-engined car is a drastically different, worse, experience than one with a piston engine. Generally you just get in and drive.
Wankel engines are just one of (surprisingly many) technologies that were more-or-less viable but just not able to become dominant. Like, we would all still manage to drive around if the only technologies developed happened to be opposed-piston engines, or two-stroke diesels, or axial-cylinder engines with a swashplate. We might even see a few of them come back if the market moves towards series-hybrid vehicle setups. A light little rotary always running at its peak-efficiency speed might be a reasonable choice for a range-extender/series hybrid.
Rotary engines do not "leak oil", they burn oil a modest amount of oil by design. If you think about it, there really wasn't another way to lubricate them.
Practicality was pretty low, though, as you rightly point out.
Rotary engines do not "leak oil", they burn oil a modest amount of oil by design.
I was thinking of the seals, which by about 50K seemed to be a common failure point. But, yes, they did burn a bit by design; no argument there. OTOH, a lot of Wankel defenders in this thread mention RX-8s. I'm remembering RX-7s, and the economy cars that used the Wankels. Those economy cars of the 70s are where the Wankel reputation for poor fuel mileage comes from. Cute TV commercials ("piston engine goes 'boing, boing, boing', Mazda engine goes 'hmmmmm'"), not really the best engine choice to go up against Honda and Toyota at the time.
Little known fact is also that conventional piston gasoline engines are also expected to burn an amount of oil by design, particularly if given a hard usage.
It's always nice to be home in Prague from Munich in 2.5 instead of 4.5 hours in exchange for just 1.5l/100km more consumption (and going 250 (155 miles per hour) instead of 130 km/h).
Isn't there an 130 kmh speed limit on Czech highways? I wouldn't trade two hours of my life for being killed and potentially killing others in a car accident. I also quite understand that Germany has highways without a speed limit, considering that 40% of their GDP comes out of the automotive sector.
We have the big and beautiful 280 between Mountain View and San Francisco, and I thank goodness every time I make my way to the city for it. I'd never go the speeds on my bike I do on 280 anywhere else, but it's just such a gosh darn huge road I get to make a 45-60 minute trip in like 30 minutes.
It very much depends on where in the U. S. one is at. East of the Mississippi River (eastern U. S.): I'm a good boy who doesn't do more than 10mph over the limit. The exception is Ohio: if I can't avoid the state completely, I do THE SPEED LIMIT.
Western U. S.: whatever I think I can get away with. IOW, if I can see for multiple miles with few cross roads and driveways, then it's whatever I feel comfortable with. Though with western speed limits of 70mph and up, one can comfortably get away with 85mph, which is fast enough for me. Much beyond that, on the bike or in the car, and it gets tiring and the difference in fuel efficiency is huge (28mpg or less at "spirited" speeds on a bike that normally gets 42-45mpg). And the last thing one needs in a vehicle with a 5 gallon tank, and an area with few gas stations, is poor fuel efficiency. With increased fuel stops, I'm not convinced that one saves a minute of time after a point.
In this instance, think of the U. S. more like the EU. We have Montana and Nevada, they have Germany. We have Ohio, they have (for lack of a better example) the U. K. with speed cameras everywhere (yeah, yeah, Brexit; bear with me for this example).
Lol, I bought my RX-7 from an Ohio state trooper, in Ohio, and we raced the entire 2.5hr trip out of the state, in the rain. I think he called his buddies to leave us alone.
The European country you're looking for for your Ohio-equivalent example is Switzerland (sorry dudes but I've never seen police so strict to the point of silliness anywhere else in Europe).
That's actually a big question I have as a new Californian. In Houston, you got caught, every time, if you sped on the freeways. The cops were everywhere.
Here not only do I rarely see cops, I've read in the local papers that cops can't pull people over for speeding if EVERYONE is speeding. You have to be speeding far above average. So everyone is actually incentivized to speed together.
When I first got here I saw comically low speed limit signs - as low as 55mph on freeways! And averages of 65! That's INSANELY slow for how big these freeways are! But apparently it doesn't matter in California, here everyone just speeds and is protected as a group.
I don't doubt that I'll pay my dues eventually. You don't get away with 95mph on a sportbike forever. We make targets of ourselves. That's fine, in Houston I got ticketed ~200USD every three years or so, that's a fair price to get to go above the speed limit for me.
I usually go at 75-80 on a "55" highway for my daily commute, never had issues even while passing cop cars. In general, as long as you're not driving like an idiot (switching 3 lanes without signalling) or running old tags, or basically have a red flag hanging, they won't bother you. Although if they do stop your for one of these reasons, they'll probably also ticket you for speeding. Speed limits are enforced far more strictly in residential areas though.
Huh? My rotary doesn't leak oil. Mileage is an issue but not significantly worse than other sports cars of that era or even today.
I also could probably connect you with a good rotary mechanic (or several) in all 50 states plus Puerto Rico (hell, especially Puerto Rico)
The biggest issue with the FCs isn't the engine, it's the reliability of the electric systems and heat (as a distant second). With the FDs it pretty much the twin turbos. And with early RX-8s (04-early09) it's a lack of proper engine lubrication due to a design flaw.
Did they get the rotary to be usable? I thought even at its best, it was finicky and temperamental. I have never owned or driven one, just doing some idle reading online, so asking this as a serious question.
Lots of torque, lots of pep, though from what I heard, the US version (mine) had substantial increases in pollution controls which hobbled the car. Always first off the line when I wanted to be.
Yes, it burned oil by design. I'd add a half-quart of non synthetic 5W-20 maybe every 1000 miles. The rear bumper required additional car washes, as it'd get a black film, no doubt from cold starts. That wasn't much of a problem.
The big issue it had was flooding the engine. To trigger the condition, turn on engine, let it run for less than 1 minute, and turn it off (like pulling it in or out of a garage). Unless you floored it in neutral before shutting it off, the car would end up near-bricked.
The fix was to have it towed to the dealer where they'd clean out the engine for a few hundred dollars. Later I learned you could tow-start it if you could get it up past 20mph. It'd put all kinds of foul smoke out the back when you did that but in terms of hassle, it was much better.
The car had a POS OEM fuel pump under the rear seat. On hot days you'd get a vapor lock. Not the rotary's fault. Took years to find that problem, and didn't get very long with the fixed version before the stork came and the rotary had to leave.
> The fix was to have it towed to the dealer where they'd clean out the engine for a few hundred dollars. Later I learned you could tow-start it if you could get it up past 20mph. It'd put all kinds of foul smoke out the back when you did that but in terms of hassle, it was much better.
You don't need to do all that. You can just pull the EGI INJ & EGI COMP fuse, crank it for a few seconds, replace and start it up. Many folks put a bypass switch inside the car so they don't have to get out and do it. Works great.
On the RX8 at least, if you hold the gas pedal to the floor while cranking, it disables the fuel injectors. No need to pull fuses.
* Foot to floor, crank for 10 sec,
* let it rest for 30 sec to cool off the starter,
* foot to floor and start to crank, pull your foot off the gas pedal.
Mazda sort of assumed their drivers would read the manual and drive the car properly. I think this workaround was figured out at some point in the 90s anyway.
First off, I agree that the backseat was exceptionally roomy for a 4-door coupe. For adults.
Once you have your first, you realize very quickly that babies come with a LOT of stuff. The first carrier for newborns sticks out a LOT from the back of the seat. The sorcerers at Mazda Engineering made it comfortable for tall people in the backseat by compensating for limited front-back space by using up-down space. This made it impossible for use for an infant unless the front seat was scooted all the way up.
But then there's the stroller. Good luck with that in the comically small trunk opening. Bags of stuff, boxes of stuff, yes, these things are non-optional, and they don't fit in that car, especially all at once.
The final nail was the fact that it's kinda hard to insert a child plus carrier into the backseat with your hands full. Having it back there would've been easy. Getting it back there wouldn't have been. Retrieving it, even more difficult.
After you make your peace with the above, and still manage to cram everything in, bear in mind you still need two adults, not just the driver, to fit in the car at the same time.
We could've done it, somehow, but it was smarter to sell it and buy a cheap used SUV, with plenty of room for everything. It also bears mention that I had used that car as a daily driver for 10 years.
You should have held out on the wait-and-see. The moderate-sized rear cabin with those little suicide doors (you are talking about the RX-8, aren't you?) is absolutely great for baby and child seats.
Also, yeah, I had my RX-8 tow started once. The recovery guy actually suggested I drive his truck while he sat in the car and tried to start it. So there I was with the new experience of driving an enormous full-size recovery vehicle, getting quite concerned as I looked in the mirror and saw clouds of white smoke pouring out of my car's exhaust! But, once properly wary of flooding, the car didn't give me any trouble before or since.
I have an 8 (and am involved in sports car things as a hobby) and I find the back seats to be superior to almost all sports cars and most mid-sized normal cars for seating adults.
More or less usable. They did have a tendency to blow apex seals after 80k miles, which was could end up as a full rebuild of the engine. As far as how finicky a rotary can be, the biggest thing to do is let them warm up before driving, and let them cool right down after you're done. They were never an engine to replace the standard fourbanger, but they weren't any more finicky than say a BMW or Audi at the time of the RX-8
weren't any more finicky than say a BMW or Audi at the time of the RX-8
YMMV, but my E46 BMW has been very reliable compared to an RX-8 bought at the same time. Audi was still in the process of applying the lessons of the RS4 to their everyday cars, but I still wouldn't call the RX-8 reliable compared to its peers. As you hinted, there are a couple of problems that lead to full rebuilds before 150k miles.
Mazda shot themselves in the foot reliability-wise with the first generation RX-8 because they:
* Underspec'd the ignition coils
* Didn't do enough on-road reliability testing
* Lowered the oil pressure and removed OMP ports
* Designed the oil filler breather in a way that allowed oil into the intake
In '04, the first wave of RX8s were coming in to the dealerships after 30k with severe misfire from the coils going bad. Mazda didn't have this failure mode in their factory service manual, so the cars got replacement engines (poorly reman'd in Mexico, not made on the Mazda Japan line). These didn't last because of poor manufacturing. Once the coil issue was figured out, the 8 became much more predictable and reliable.
As noted by Busterarm, they fully got their act together with the series 2 update.
Heh. I mean an engine rebuild at 80k seems kind of crazy. I am both continually amazed at the ICE and at the same time can't wait for it to die out. It's such an archaic technology. Hell, a turbine engine would be so much more fun to have in a car!
It was not, in the end, a production car, but there was a lot of data gathered as to performance and reliability in real-world settings.
Not too long ago, Jaguar had a concept CX-75, which was a hybrid mid-engined supercar where the piston engine was replaced with two Bladon Jets micro gas turbines. After 2008, they didn't want to commit to an expensive limited production vehicle, too bad.
Damn. That sounds like they almost made it work. I wonder how those cars would have done with corn ethanol. Electric boost for initial acceleration and better heat exchangers would have probably completely eliminated the remaining problems with them. Thanks for the link!
Turbos are definitely taking hold in the American auto industry as well, with stuff like the Chevy Sonic and Fiesta/Focus really making good use of them with tiny engines. The 2015 Focus had an option for a 1L, 3 cylinder engine with a turbo for commuters. Great stuff.
The rotary was never invented by Mazda, it was invented in germany and applied first by NSU.
Then it was licensed to many manufacturers, among which there was Mercedes-Benz, which was the manufacturer who got solved first the apex seal problem, and in the late 70s with the C111 prototype car, the first manufacturer to create a side port wankel engine (which mazda would only show on the RX8 decades later) and a 4-rotor engine (which mazda would only show on the 787 racing car in 1991.
Then MB ditched the wankel engine because of low fuel efficience, something that ultimately led to mazda doing the same... in the 2000s.
Compression ignition is more an evolution than a revolution -- it's an iterative improvement on an existing technology.
Skyactiv exists in the first place because Mazda does not have the money or engineering resources to build a hybrid or electric car by themselves. I suspect that in a decade or two, Mazda's decision not to start building hybrids and electric cars when the other major brands were doing so will be regarded as a serious mistake.
investing in high efficiency gasoline engines is a much better bet. the world will be running on gasoline for decades at least. even if europe (doubtful) or US (very doubtful) pull out of gasoline there will still be billions of potential customers around the world.
I consider the headline slightly misleading, since compression ignition engines that run on a variety of fuels, including gasoline, were relatively popular around the turn of the century:
Another big attraction with the hot-bulb engine was its ability to run on a wide range of fuels. Even poorly combustible fuels could be used, since a combination of vaporiser- and compression ignition meant that such fuels could be made to burn. The usual fuel was fuel oil, similar to modern-day diesel fuel, but natural gas, kerosene, crude oil, vegetable oil or creosote could also be used.
I think this is a great step forward for ICE . Combining this technology into generators (and cars like chevy volt) will make an extremely convenient and fuel efficient vehicle.
Technologies are always at their best when they're already being obsoleted. Just as electric cars become practical ICEs are getting great and so are the transmissions, making for great modern powertrains.
There were rumors last year in F1 that one of the manufacturers was doing HCCI for it's engine (the same that Mazda has done here). I don't think any actually did but Ferrari did introduce a jet ignition system[1] that allows them to run much leaner. I wonder if anyone is thinking of adapting that to normal road cars.
So how exactly does this work? And why is it more effective and how does it allow you to run super lean while producing the same amount of power? Also, presumably running lean would mean lower emissions, but is that really true?
Running lean, highly compressed, and highly efficient reduces expected production of carbon monoxide and residual hydrocarbons. But it significantly increases nitrogen oxide formation, as in diesel engines. So I wonder how the emissions control system deals with the extra NOx -- that has (see Dieselgate and continuing related fallout) proven quite a sticky problem for high efficiency diesel engines in passenger vehicles. The cheap "solutions" were mostly cheats and the actual solutions cost more.
Maybe this is old news to people who pay attention to car news, but the most interesting thing to me is this line from the press release:
> From 2019, start introducing electric vehicles and other electric drive technologies in regions that use a high ratio of clean energy for power generation or restrict certain vehicles to reduce air pollution
I've been kind of disappointed that Mazda hasn't gotten into the electric car market yet; I'm glad to see they're coming around.
Mazda is kind of small, it would be like expecting an electric vehicle from Subaru. Ya, it will happen eventually, but the big guys are going to have the resources to go first (well, and startups built on the concept itself).
Also, hydrogen was supposed to be the big clean fuel in Japan, but that fell by the wayside when the bigger Chinese market decided it would be electric.
Keep in mind that the electric section of the overall car marjket is just 1-1.5% right now. It's just not a significant market right now. Making an electric car is only good for building know-how.
In the industry, the Chevy Bolt is expected to be the first electric car to end up being profitable. Next year's Audi Q6 e-tron quattro (what a name...) is expected to be the second. They are the first specimen of a new generate of electric cars that are for-profit mass production products from the ground up. By 2025 virtually every car manufacturer will be competing seriously in the electric market.
This generational change is happening because as batteries and fuel cells are getting cheaper rapidly. We are coming up on the cross-over point where an electric car can be made profitably right now. But this also means that there was no point for the likes of Mazda to even work on electric cars before now.
SKYACTIV-X is the world's first commercial gasoline engine to use compression ignition, in which the fuel-air mixture ignites spontaneously when compressed by the piston.
Just pure curiosity, I wonder if SKYACTIV-X engine would also also consume diesel or gasoline/diesel mixtures?
I suspect that when operation in compression-detonation mode, it will inject the fuel late enough into the compression stroke that the difference between 87 and 97 octane fuel won't be that big of a deal.
If it does make a difference then I would expect they would design for the higher octane rating gas to prevent user-error.
I anticipate the engine's control computer will be able to adapt in any case. It's like the Mercedes driver who puts in 87... it'll work, and the gas is cheaper, but the tradeoff is the engine runs in "poor fuel" mode and is less efficient, eliminating any savings.
I'd like a similar repository, for all the predictions made by electric-car proponents about when all ICE units will be phased out, and by what date. Especially when predictions are made regarding the viability of this or that gascar company who is seen as being insufficiently hitched to the electric bandwagon, as though powertrain technology was the alpha-and-omega of carmaking.
Gah, terribly confusing terminology. This is a Diesel engine. "Compression ignition" is what the Diesel cycle is all about. It's just carefully tuned such that it can run on gasoline instead of kerosene (i.e. "diesel fuel").
And mostly I don't get it. This is just a convenience factor. If you want a high-efficiency diesel right now you can buy one already. Low-volatility fuels are already more energy-dense (i.e. fewer losses carrying the stuff around in the tank) and require less energy to refine. This gives you the advantage of being able to pull into a gas station without diesel available, but otherwise doesn't seem to add much.
It's not exactly the same as a diesel engine. Diesels use a stratified charge (SCCI), meaning fuel is injected at the end of the compression stroke and burns immediately, without having a chance to mix thoroughly with the air. This engine uses a homogeneous charge (HCCI), meaning fuel is injected at the beginning of the intake stroke but does not ignite until the end of the compression stroke, therefore having time to mix with the air. This subtle difference makes the engine much harder to control, but should yield lower NOx and particulate emissions as well as higher power output.
Also, the engine is capable of running in HCCI mode under light-ish load. It still has spark plugs, and can run as a normal gasoline engine (HCSI) when high power is demanded.
This is much more interesting than that. It's a gasoline engine (fuel injected at intake and spark to ignite) that can operate in compression ignition in some of its range and thus get better mileage[1]. It should get efficiencies much similar to diesel but me much cleaner (less NOx).
Yes, however common diesel fuels tend to be higher in NOx and particulates.
My understanding is that because gasoline is refined to a higher degree it burns a fair bit cleaner in similar environments(and also makes it a PITA to store for more than a few months).
[edit]
We've got a pair of tractors around the house here, '81 diesel(pre-emissions), and '47 gasser.
I can tell you which one I prefer to run from an exhaust perspective, the diesel may have torque and is a dead-simple engine but you don't want to be downwind of it when cutting heavy brush.
NOx emissions from a diesel engine are from atmospheric nitrogen and oxygen, not from the fuel. I welcome further clarifications, but my understanding is that this engine will not produce NOx like a standard diesel because the fuel/air mix will be tightly controlled like in a gasoline engine, and temperature and pressure will be significantly less than a standard diesel. Additionally, it seems the timing of the fuel injection will be much earlier than a diesel, resulting in more complete air/fuel mixture; this is possible because gasoline has a higher ignition temperature, so fuel can be injected early and ignition won't happen until the compression stroke; diesel fuel would ignite during injection regardless of where in the cycle.
I'm struggling with the same reasoning: NOx is the result of high combustion temperatures, which is a pure function of the compression ratio (and fuel mixture), which is the thing that defines the high efficiencies you can get with a diesel cycle.
The argument in the linked wikipedia entry is that combustion temperatures are lower in this cycle because the better fuel/air mixing means it can burn much leaner and thus at a lower temperature. But a leaner mixture means lower power for a given displacement too, which means lower efficiency than a comparable traditional diesel (which are already hard-pressed to see gains like the 40% claimed against well-tuned gas engines).
Honestly the whole thing sounds very snake oily to me. I don't deny that it's possible such a thing could be tuned to operate as well as a traditional engine, but... it sounds awfully fiddly. I'd want to see numbers from a production engine in a real car before placing any bets. Electric continues to look like a much better bet to my eyes.
I don't buy the wikipedia argument either, but I do believe the homogenous charge mixture will burn at a lower temperature for a given compression ratio than the equivalent stratified charge.
Throwing f/a into the mix, the HCCI mode is apparently only active during low-power cruise, so the lean mixture is fine. The Mazda innovation is controlling the changeover from HCCI to SI when more power is demanded.
Diesel seems to be very much on the way out, with several cities discussing diesel bans. If I was to buy a new car today I certainly wouldn't consider a diesel (as opposed to two or three years ago when diesel was the future)
So this is 'gasoline' diesel. Or diesel without the NOx. Which, in theory, would give better fuel economy and possibly better torque. And it will ship in cars in the 2019 model year (so possibly as early as late next year).
To me, it sounds like a "Don't pass"[1] bet on electric cars. Which they also are working with Toyota on electric cars so perhaps it is a fall back plan. It will be interesting to see how it fares. There are a lot of products that are built as the other side of an industry change bet. Sun created a workstation on the 68040 in case the SPARCStation didn't meet expectations as an example.
[1] In the dice game Craps, the "Don't Pass" bet is against the current player 'winning.'