
Mazda hopes to achieve 56% thermal efficiency with gasoline engine - hliyan
https://www.popularmechanics.com/cars/car-technology/a15915023/mazda-skyactiv-3-gas-clean-as-ev/
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jerkstate
I'm glad the article references Formula 1 engines. The current generation is
really a technical marvel, and was the first thing to come to mind when I read
this headline.

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userbinator
[https://en.wikipedia.org/wiki/Brake_specific_fuel_consumptio...](https://en.wikipedia.org/wiki/Brake_specific_fuel_consumption#Examples_of_values_of_BSFC_for_shaft_engines)

56% is slightly more than the efficiency of very large low-speed two-stroke
diesels (one of the most thermally efficient piston engine types), so I remain
very skeptical.

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pasbesoin
Stick one in a well-made plug-in/hybrid, and I'm sold.

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DrScump
Can this principle be applied to ICE using other fuels, like ethanol?

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petre
It works. Even with wet ethanol.

[https://escholarship.org/uc/item/6cd5b6vq](https://escholarship.org/uc/item/6cd5b6vq)

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ggm
Good to have stretch goals. EV have stretch goals too, as do battery tech
designers and power generation and storage. So.. given this is a 25 year
stretch goal, what will EV look like then? I think we can predict they will be
better than this 57% heat efficiency or not.

I like phev as an interim, but Mazda have to invest now to have a story in
phev. This incredible goal in ice engine efficiency could be part of that.

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lafar6502
what kind of heat efficiency you mean?

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ggm
The Carnot heat engine efficiency. That's what the 57% is talking about in the
proposed improvements Mazda are projecting. Getting a single F1 engine there
for a circuit is one thing. Getting a road car under varying driven conditions
there, on a production line.. that's another. If the 57% was demonstrated
they'd have said a deadline inside 25 years. If they project out more than
Five, it's a bet, not a certainty.

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jxub
Mazda is for me quite an admirable example of traditional car company, esp.
compared to the likes of Volkswagen, as the ratio of quality/economics is
really good and their new designs are gorgeous given the price range.

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jagger27
> their new designs are gorgeous given the price range.

Definitely. Compare their designs to anything else from Japan and you'll find
that they manage to be modern and interesting without being too angular and
aggressive (see new Honda Civic, esp. the Type R and the Prius Prime).

Besides that, their driving experiences are tuned for pure joy. The CX-5 is by
far the best handling mid-size SUV, and of course the MX-5 is unmatched. Best
of all, they still somehow find the time to experiment and create masterpieces
like the MX-5 RF.

Now if only they can deliver on Apple CarPlay and Android Auto, then they'll
really check all the boxes.

Source: a 2017 MX-5 soft-top was first brand new car.

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vesrah
To be fair, the CTR is a car meant to appeal to a certain audience. Mazda
sells nothing that caters to said audience.

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vinay427
They had the MazdaSpeed3, which didn't look nearly as polarizing as the
current CTR. Granted, neither did the previous Civic Si or Type R.

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theothermkn
Eventually, you'll run up against the limit defined by the Carnot efficiency.
I wonder where this engine will stand in relation to that. Will they be able
to burn at a higher temperature in order to drive the raw efficiency up?
Perhaps with a improved catalytic converter? Or are these all improvements in
internal friction?

What does the technology actually look like? The article was frustratingly
scant on details.

Ah. You can track down the video explanation:
[https://www.youtube.com/watch?v=N_No3KSaTrM](https://www.youtube.com/watch?v=N_No3KSaTrM)

Contrary to the appeal to the layperson's mechanical intuition in the video,
they give away that they are apparently speeding combustion at the top of the
stroke, resulting in a better approximation of "constant volume heat
addition." This will result in a higher top temperature in the combustion
chamber, and is the real reason for their "pushes longer and harder"
explanation. This will come with added NOx production, so they'll have to have
better catalytic conversion, with a couple caveats. It _may_ be that the
emissions rules are on a per-mile basis, so that the total NOx of the engine
is lower per mile because less fuel is burned. They may also just be hitting
markets with laxer restrictions.

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thibautg
There was a nice explanation in an article from Ars Technica a few days ago:
[https://arstechnica.com/cars/2018/01/mazdas-skyactiv-x-
shows...](https://arstechnica.com/cars/2018/01/mazdas-skyactiv-x-shows-the-
internal-combustion-engine-has-a-future/)

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aidenn0
That's the Syactiv X which will not achieve 56%. This article is for the
following generation (Skyactiv 3)

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craftyguy
They should probably stop investing so much in an engine that requires fossil
fuels to operate.

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sz4kerto
Stopping investing into a technology that is probably going to dominate the
industry for the next 25 years might not be too smart. (EVs are coming, but
they're quite far from accounting for >50% of the total vehicle sales.)

It's a bit like telling Microsoft in 1990 that focusing on PCs is stupid
because mobile computing is coming for sure. :)

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kjksf
You call it domination, I call it slow decline.

Many governments have announced that by 2040 it'll be illegal to sell cars
with such engines.

They certainly won't be dominating in 22 years.

The question is not "is this business going to be dead" but "when this
business will be dead".

So it's more like telling MicroPro to to stop investing in their cash cow DOS-
based WordStar and port that app to Windows, because the writing is on the
wall.

MicrPro and many other companies were a bit asleep at the wheel during DOS ->
Windows transition and that's why there's no MicroPro anymore and there's no
WordStar anymore.

Transition to electric motors will take a bit longer but the window to become
a significant player in new technology is not infinite.

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semi-extrinsic
> Many governments have announced that by 2040 it'll be illegal to sell cars
> with such engines.

That's very much incorrect. What they've all said is that it will be illegal
to sell cars _with only such engines_. In particular, plug-in hybrids will be
allowed, and will probably be the biggest success both commercially and for
the environment.

I mean, if I can have something like the latest Mercedes C350e or BMW 530e,
but with a bit faster charging and a ~50 mile electric range, that's going to
beat an electric 300+ mile range car any day of the week once the subsidies
start wearing off (which is a lot sooner than 2040).

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kjksf
The estimate is that by 2020 battery prices will come down to make the price
of electric engine + battery be the same as price of diesel engine.

Even with relatively slow progress on batteries, they double in density / get
half as cheap in about 5 to 10 years.

Add to this that Tesla is aggressively doubling their Supercharging network
every year.

If cars today have 200-300 miles of range, in 10 years they'll have 400-600
miles for less money, eliminating the one issue that stands in the way of mass
adoption of evs (range anxiety).

Most likely 7-12 years from now it'll make no economic sense to put 2
different engines in the same car i.e. a single electric engine will be
cheaper than a hybrid.

And this is based on linearly extrapolating the past. If battery production
follows the same curve as wind / solar energy production, we're systematically
underestimating progress and things will happen faster.

We're really in Day 1 of mass producing batteries, with volumes (and therefore
investments in improvements) scaling way faster than linearly.

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cellularmitosis
I thought we don't have enough lithium to transition the world's autos to
electric?

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acct1771
You thought wrong. Especially with improved (any) recycling processes.

