Cleaner than electric? Mazda talks up gasoline engine fuel economy ambitions for SkyActiv 2

Mar 29, 2014 by Nancy Owano weblog

(Phys.org) —Auto-focused sites are buzzing over a recent report in Autocar, reporting Japanese automobile manufacturer Mazda's future gasoline engine technology, which will reduce carbon dioxide emissions below the amount generated to power electric cars.

As Geek.com noted, while do not pump out CO2 as they travel, they have a carbon footprint created when the electric power they run on is produced. Though not due for some years to come, the very idea of a gasoline engine efficient enough to release less carbon dioxide than an electric car was tantalizing enough to make the numerous blog and car site headlines. Specifically, the spotlight is on advances in Mazda's SkyActiv engine technology. Mark Tisshaw, writing in Autocar, said "So efficient is its latest internal combustion engine technology, the Japanese firm claims that it could even eclipse pure electric cars for well-to-wheel CO2 emissions, without adding expensive and heavy hybrid or plug-in hybrid components."

At Mazda, the engine of the future is called the SkyActiv-G Generation 2, a follow-up to Mazda's SkyActiv-G Generation 1. For SkyActiv-G Generation 2, Mazda will adopt homogeneous charge compression ignition (HCCI) and an even higher compression ratio of 18:1 over SkyActiv-G Generation 1 high compression ratio of 14:1. Mazda said on its site that increasing the compression ratio considerably improves thermal efficiency. According to Autocar, it is likely SkyActiv-G Generation 2 technology could arrive in production before the decade is out..

For SkyActiv-G Generation 2, Mazda will adopt homogeneous charge compression ignition (HCCI) and the higher compression ratio of 18:1. Autocar said The HCCI system works in a way similar to a diesel engine, using piston compression rather than a spark plug to ignite the mixture in the chamber.

Automotive News explained how HCCI "compresses the fuel-air mixture to such a high pressure and temperature that it ignites by itself without requiring a spark, similar to the way a diesel engine operates."

That Mazda had ambitious plans for a generation of engines in years to come that could achieve 30 percent better fuel economy than the current line of Skyactiv engines was already evident back in January this year, when Mitsuo Hitomi, in charge of powertrain development, spoke at Mazda's Yokohama technical center. Discussing goals, Hitomi said Skyactiv 2 will focus on improved internal combustion "If we want to dramatically improve fuel economy from here, the only route is through lean burning," Hitomi referred also to plans for a Skyactiv 3 lineup in the future that may help Mazda comply with 2025 emissions targets.

Explore further: First of four Fukushima reactors cleared of nuclear fuel

More information: www.mazda.com/technology/skyactiv/engine/

add to favorites email to friend print save as pdf

Related Stories

Mazda to showcase i-ELOOP fuel-saving braking system

Nov 27, 2011

(PhysOrg.com) -- Mazda has announced what it claims to be the world’s first capacitor based regenerative braking system, as a unique fuel-efficient solution for passenger vehicles. The system is called ...

Ford Fusion wins LA car show green prize

Nov 29, 2012

The 2013 Ford Fusion was named Green Car of the Year Thursday at the LA Auto Show, as the US carmaker boasted having gone from "laggard to leader" in the environmentally-friendly vehicle market.

The efficient choice among combustion engines

Sep 12, 2013

(Phys.org) —Researchers at ETH Zurich have developed an internal combustion engine that emits less than half the CO2 compared to a regular engine without compromising performance. This corresponds to fuel ...

Recommended for you

Fuel cells to connect our smartphones to the outside world

5 hours ago

The potential of hydrogen and fuel cell applications goes way beyond the development of green cars. The FCPOWEREDRBS team is determined to prove this with a Fuel Cell technology to power off-grid telecom stations. They believe ...

The state of shale

Dec 19, 2014

University of Pittsburgh researchers have shared their findings from three studies related to shale gas in a recent special issue of the journal Energy Technology, edited by Götz Veser, the Nickolas A. DeCecco Professor of Che ...

User comments : 41

Adjust slider to filter visible comments by rank

Display comments: newest first

baudrunner
3 / 5 (1) Mar 29, 2014
From a Wikipedia article about Homogeneous charge compression ignition:
The unburned hydrocarbon and carbon monoxide emissions are still high (due to lower peak temperatures), as in gasoline engines, and must still be treated to meet automotive emission regulations.
Lean burning is good, but apparently still needs to use a catalytic converter to eliminate pollutants.
Eikka
3.6 / 5 (5) Mar 29, 2014
If it's a diesel engine in principle, why not go the logical next inch and make a diesel engine? What's the advantage of running on gasoline?
jimbo92107
1.5 / 5 (2) Mar 29, 2014
Sounds like a good candidate for biodiesel. Or some other non petroleum, renewable fuel.
Mike_Massen
1 / 5 (2) Mar 30, 2014
Do people not see the obvious chemical incongruity here ?

If this engine is designed to run on the same (or similar) fuels we already use, despite the fuel's octane & despite engine's high compression ratio - then you cannot defeat Chemistry - you WILL get the same amount of CO2, though it might end up delivering exhaust at different temp.

So therefore, to claim:-
..reduce carbon dioxide emissions below the amount generated to power electric cars
per-supposes a major change in fuel & significant indeed.
ie. The fuel must have a greater proportion of H to C than contemporary conventional 'gasoline'.

OR, they are spitting out more CO, which of course is a flaky way to reduce CO2 ;-)

Either that or their metric for
..below the amount generated to power electric cars
needs some serious attention & re-evaluation & useful robust dialectic firmly founded on the Chemistry & of course the Physics of just how much bang for buck we are actually likely to get !

Questions ?
Foundation
5 / 5 (6) Mar 30, 2014
Mike, obviously you'll get the same amount of CO2 per liter gasoline burned. I believe the point is that you could drive 30% further for the same amount of gasoline.
mikael_murstam
2.8 / 5 (6) Mar 30, 2014
Even if it would release less CO2 than an electric it would still release it in the city and it would hinder the development of more green electric sources that would continue making the electric car more and more green. It is ridiculous to think that this would be an alternative to an electric vehicle because of that fact.
Eikka
3.3 / 5 (7) Mar 30, 2014
Even if it would release less CO2 than an electric it would still release it in the city


CO2 in itself is not a problem. It doesn't contribute to smog or cause any adverse health effects.

it would hinder the development of more green electric sources that would continue making the electric car more and more green


How? Electric cars aren't exactly the driving force behind advanced renewable energy sources. They just increase demand and make it harder to meet the existing load on the grid.

80% of the world's electricity is still produced with coal, and will be for years and years to come, so there's no point in building fleets of electric cars before they have a clean source of energy. Switching to higher efficiency engines and using natural gas for fuel allows you to reduce emissions faster than building electric vehicles.
dvdrushton
3 / 5 (6) Mar 30, 2014
80% of the world's electricity is still produced with coal,


Would you have a source for that stat Eikka?

I found a number that was about half that - http://www.worldc...tistics/

Almost all of the capacity being added to the grid in countries like the U.S. is renewables - so that balance is changing. There are proposals on the table to have all of our power be from renewables by mid century - http://theenergyc...-century

Surely we should not let the perfect be the enemy of the good.
PPihkala
1 / 5 (2) Mar 30, 2014
This is peanuts. Until we get weaned out of gasoline, I would suggest that we use MYT as the engine for cars and even flying. Just google 'MYT engine'
Jizby
Mar 30, 2014
This comment has been removed by a moderator.
Eikka
4 / 5 (8) Mar 30, 2014
I found a number that was about half that


Then I stand corrected, but does that really change the point? The US makes 71% of electricity using fossil fuels, 49% from coal, 21% natural gas, 1% petroleum.

Almost all of the capacity being added to the grid in countries like the U.S. is renewables - so that balance is changing.


Not really. The peak-to-average ratio of wind power is around 4:1 and for solar power 8:1 and up to 10:1 which means that after about 20% grid penetration it starts to cost exponentially more to use more because we have no storage capacity to capture and use the surplus peak production.

And batteries have significant inherent energy cost (ESOI) which is not counted in.

all of our power be from renewables by mid century


Unlikely.

Even if electricity became clean enough by 2050, that's still 36 years and many generations of cars from now. EV's are a niche product for areas with lots of hydro and nuclear. Elsewhere they just do more harm.
KBK
1.7 / 5 (3) Mar 30, 2014
HHO assist in cars is still more economical, as it can be done with today's engines; it has been proven by many. We're getting into the tens of thousands, here.

It also burns cleaner than this 'invention'. Much much cleaner. Zero effluent, which only brings up questions. Questions which have been answered, if you search for it. The minimal answer is: transmutation.

The data behind HHO assist is compelling.
NoTennisNow
1.5 / 5 (2) Mar 30, 2014
My thoughts,
(1) need a cradle to grave CO2 foot comparason for the new engine that considers the global market penetration
(2) get rid of the "feel good" mantra for these engines (I'm doing my part buying green cars) and get serious about global CO2 emissions,
(3) see 1 and 2
dvdrushton
2.3 / 5 (6) Mar 30, 2014
Then I stand corrected, but does that really change the point?


You would surely agree that 80% and 40% are very different numbers - and that you are clearly happy playing loosely with the facts. The bigger point being that we do need to get off of fossil fuels. The WHO reports 7 million deaths a year from pollution - http://www.cnn.co...-deaths/ Closing coal plants is clearly an important thing to do from a perspective of health - http://cleantechn...h-shows/

Absolutely there is an issue with intermittency, and rushing too fast into renewables has some problems. Perhaps countries like Germany and Denmark are giving us the experience we need to figure out how to do this right.
Duude
3 / 5 (5) Mar 30, 2014
We aren't even including the larger carbon footprint created in mining and manufacturing the LI-ion battery.
dedereu
1.5 / 5 (2) Mar 30, 2014
With "HCCI system works in a way similar to a diesel engine, using piston compression rather than a spark plug to ignite the mixture in the chamber" apart the fuel, what is the difference with a diesel engine ?
And why there will be less particle and pollution than with a diesel engine ?.

PPihkala
2 / 5 (2) Mar 30, 2014
Please google up the MYT engine, which is real evolution in ICE. It is much smaller, has less parts and uses less fuel for the same power output, therefore it is greener.
AlexCoe
2 / 5 (3) Mar 30, 2014
I will add to those who find the Mazda approach is the faster and more efficient means to cleaning things up. If you add ALL of the dirt that comes from both the batteries and the rare earth magnets needed to propel an all electric car, add all of it up and they are more than a conventionally powered gas vehicle. The only way the electric wins is IF it can run for many more miles than is usual for said vehicles. I don't remember the exact numbers but it's silly to even argue. There was a study done by a Norway university published here, at phys.org, that spoke to it well. http://phys.org/n...cle.html

The strain to existing infrastructure as well would crash the electrical distribution lines. We have an existing petrochemical system that is functional. If the efficiency of gasoline can be increased it might be a very viable and cleaner way to go that makes economic sense as well as treating the environment better.
dvdrushton
5 / 5 (1) Mar 30, 2014
I will just quote the conclusion from AlexCoe's own reference.

"Although EVs are an important technological breakthrough with substantial potential environmental benefits, these cannot be harnessed everywhere and in every condition. Our results clearly indicate that it is counterproductive to promote EVs in areas where electricity is primarily produced from lignite, coal, or even heavy oil combustion."

Sounds like a resounding endorsement of electric vehicles - powered by anything other than heavy oil, or coal.
AlexCoe
1 / 5 (1) Mar 30, 2014
dvd, first off, that's NOT their conclusion, read the last two paragraphs, after that one.

It remains to be seen if an EV or Hybrid vehicle will be better for the planet than a petroleum fueled vehicle or not. That very much depends on production methods and recycling as well as how the energy used in it is supplied or sourced.

It is not now, nor has it ever been a rational choice, that was easy, IF ALL the factors are figured into the equation. I'm certainly not saying they can't be a better choice, or will be, but so far, saying that it's an easy choice, is ill informed and ignorant of all the true facts involved.
dvdrushton
1 / 5 (1) Mar 31, 2014
Alex - when I see the words 'They concluded that' - I assume that it means the authors have made a conclusion - even if the 'concluded that' was a statement from another article - the fact that this author chose to repeat it - indicates agreement with the conclusion - yes?.

I agree that it is not an easy choice - as we are currently operating a very effective - but dirty power/transportation system - and we have to make complex decisions about how to clean it up. We are doing that. Are you aware that almost all new electric power being brought on line in the U.S. - is renewable? http://thinkprogr...wable-2/ I grant you that china is a different story.

If we were to begin adopting EV's in large numbers - generating capacity of the grid would have to expand - which could be done with renewables. This would cause a drop in emissions. China is working on Thorium, and renewables - their coal consumption has to drop.
ugosugo
2 / 5 (4) Mar 31, 2014
total bullshit
Eikka
3.5 / 5 (6) Mar 31, 2014


Perhaps countries like Germany and Denmark are giving us the experience we need to figure out how to do this right.


At least they're showing exactly what not to do.

Denmark is among the most polluting countries in terms of CO2 per kWh of electricity produced, in part -because- they're employing a high percentage of intermittent renewables that forces them to rely on less efficient means of energy production such as simple steam turbines instead of thermal co-generation or combined cycle plants due to the need for quick output adjustment.

That's the paradox. When you add intermittent renewables to the grid, they force you to replace baseload generation with less efficient load following powerplants and that results in an overall increase in CO2 output and pollution. One can only attempt to hide this fact by using the "virtual battery" principle, which means pushing the power across borders to be handled by other countries, so your pollution figures would look nicer.

Eikka
3.4 / 5 (5) Mar 31, 2014
The bigger point being that we do need to get off of fossil fuels.


Yes, but that's also a red herring in this particular case, because we can't. We simply don't have the technology yet.

Building more electric cars would not decrease overall pollution, because there's only so much clean energy around and the increase in demand will not be met with increase in clean energy because we can't build more hydro power, we refuse to build more nuclear power, and building more intermittent renewables just means we need to use more fossil fuel power in inefficient ways to adjust to the output variations and in the end you end up producing 70-80% of the new power from fossil fuels anyhow.

So building electric cars is just increasing demand for electricity, and that increases pollution. The best they can offer is to move the emissions to a different smokestack.

Eikka
3.7 / 5 (6) Mar 31, 2014
http://www.eea.eu...-per-kwh

The sad fact is that out of the European nations, those who use nuclear power are the least polluting. Norway of course is an exception because they have huge hydropower reserves and a small population.

The ones that don't use nuclear power produce twice as much CO2 regardless of renewables. Denmark is roughly on par with Slovenia. One has 30% wind power, the other has 1.3%.

Likewise with Germany. 25% renewables, makes as much CO2/kWh as the UK which has 11.3%. It's almost like it doesn't really matter how much wind or solar power you have because you lose efficiency elsewhere.
Mike_Massen
2.3 / 5 (3) Mar 31, 2014
Foundation got his numbers from where precisely ?
Mike, obviously you'll get the same amount of CO2 per liter gasoline burned. I believe the point is that you could drive 30% further for the same amount of gasoline.
Could Foundation, or might Foundation, some time when Foundation ?
The article states "..generation of engines in years to come.." so surely that cannot be the current engine described or are you Assuming it is, if so then why please ?

Whee did you get the 30% from Foundation in respect of the current engine ?

Re The current engine, at 18:1 CR its not dissimilar to a diesel, would it not be batter to improve the CR & & in respect of the overall package re combinatorial controls on a contemporary diesel as a starting point given many energy effective renewable fuels available or planned are already easily diesel compatible ?
dvdrushton
3 / 5 (2) Mar 31, 2014
Eikka
Denmark is among the most polluting countries in terms of CO2 per kWh of electricity produced,


Would you have a source to support your assertion. This site gives C02 output per capita - it looks like Denmark is about in the middle in terms of the EU (8.4), better than Norway (10.5), and a lot better than the U.S. (17.2) - and this information is 4 - 5 yrs out of date - and so is probably a lot better now. http://en.wikiped...r_capita

You are correct that intermittency is a problem - but not as big as you make it out to be. We are learning to integrate renewables on to the grid. We are in the throws of one of the greatest revolutions in the history of the world - the conversion to distributed - renewable energy.
Scottingham
5 / 5 (3) Mar 31, 2014
Even though the tech is similar to a diesel, the gasoline is cleaner burning with less NOx and such emissions than a diesel burning car.

I used to be all gung-ho about electric cars. I really like the simplicity of the motor versus the complexity of the piston engines. However, unless there is some fantastic revolution in battery tech, I don't see electric cars taking over any time soon.

Couple this new engine tech with the fact that alternative chemical fuels (eg bio-butanol) could plug into the already extensive liquid fuel with little or no modification...I think EVs will be a niche market for some time in the future.
Eikka
1 / 5 (3) Apr 01, 2014
Would you have a source to support your assertion.


I already gave you one. CO2 output per capita is not relevant. CO2 per unit energy is. In your example, Norway is producing a lot of CO2 per capita, but that's only because they have a small population and use a lot of energy for heavy industry like aluminium production. In reality they're about the cleanest country there is because they make nearly all of their electricity using hydropower.

We are learning to integrate renewables on to the grid.


Yes, but at the same time we are trying to run with renewables before we can walk. The new powerplants we need to build -now- to cope with the intermittency have payback times in 30-50 years, which means they're only economically feasible if you keep using them for decades. Renewable energy or not, we have to build them anyways to replace the aging stock, which means we can't get rid of the fossil fuels for another half a century.
Eikka
1 / 5 (1) Apr 01, 2014
Foundation got his numbers from where precisely ?


It says so in the article.

Whee did you get the 30% from Foundation in respect of the current engine ?


The figure is estimated for the next version. It's 30% better fuel efficiency in respect to this version, which is already more fuel efficient than regular spark ignition engines, so the fuel savings in respect to cars on the market today is greater than 30%.
dvdrushton
1 / 5 (1) Apr 01, 2014
Eikka
Yes, but at the same time we are trying to run with renewables before we can walk.


No - we are learning to walk. How long will it take? Many decades - but our fossil fuel infrastructure was not built in a day either. Your oft repeated premise that we must build fossil fuel generation to back up renewables is simply not true. Here is an example of one market that is integrating large quantities of renewables - and guess what? They do not have to build fossil fuel back up for each watt of renewables. http://www.ercot....ow/26611
AlexCoe
3 / 5 (2) Apr 01, 2014
dvd, don't you understand that wind generation kills birds? Butt loads of them if you listen to peregrine fund and condor fans. Solar gets in the way of desert tortoise breeding grounds and virtually every other renewable seems to offend some wildlife group or another.
BTW posting a press release as if it proves anything, please, go back under your bridge!
dvdrushton
3 / 5 (2) Apr 01, 2014
AlexCoe - maybe you should spend some time looking at the environmental impact of fossil fuels. Start by googling oil spills. No fuel source is 100 percent clean. What problem do you have with roof top solar? I posted a press release as an example of an energy market that is integrating large quantities of renewables - without the need for building fossil fuels to back up each watt installed - as Eikka is often stating. Yes I am passionate about progress, and renewable energy. Reality supports my position - why don't you do more reading - and less snarky commenting - maybe go back under your bridge.
Eikka
1 / 5 (1) Apr 01, 2014
How long will it take? Many decades - but our fossil fuel infrastructure was not built in a day either.


That was my point. It's highly unlikely we'll get much cleaner electricity by 2050, so a next generation of efficient combustion engines is necessary to reduce emissions until we do.

Your oft repeated premise that we must build fossil fuel generation to back up renewables is simply not true.


We can build renewables in a limited sense without increasing fossil fuel use, but the main problem is scalability and price.

Here is an example of one market that is integrating large quantities of renewables - and guess what? They do not have to build fossil fuel back up for each watt of renewables.


That's because the ERCOT region uses the virtual battery principle, which means offloading the power out of Texas to deal with it by not dealing with it.

The problem with wind power in Texas is that tends to produce at night and not during daytime peak demand.
Eikka
5 / 5 (1) Apr 01, 2014
And I dislike the term "backup" when talking of fossil fuel load following to renewable energy, because it gives a totally wrong impression of the matter. It gives the impression that the turbines are turning quite steadily and only occasionally dropping, while the opposite is true: the turbines are making high brief power surges with long gaps in between, and the conventional power generation has to fill these gaps in. This is a direct result from the high peak-to-average ratio.

Here's a good representative picture of wind power output from Ireland:
http://www.withou...e213.png

dvdrushton
1 / 5 (1) Apr 01, 2014
Eikka -
That's because the ERCOT region uses the virtual battery principle, which means offloading the power out of Texas to deal with it by not dealing with it.


so any time someone shows you a real world example of the success of renewables - you come up with a rationalization as to why that is not a good example. No one is suggesting that we can transition immediately to renewables - it is going to take many decades. No one is suggesting that we use just wind. Yes - wind is intermittent - just like solar - so requires strategies to integrate it into our power mix. There is plenty of real world example - as well as study - to show that we can do it - http://www.civils...ease.cfm

You are aware right that demand curves for power are not flat lines right? - they meander all over the map. So conventional fuel systems have to be built to supply enough power for peak demand - and then shut down, dump power, or store power - when demand drops
dvdrushton
not rated yet Apr 01, 2014
So intermittent sources complicate the picture - but the challenges are not insurmountable - we have a lot of experience already under our belt - and we are just on the first rung of the ladder. What is your need to promote fossil fuels? Are you not aware of the double issue of pollution - http://www.livesc...ths.html - and climate change. There is great research going on with Gas/solar hybrid systems - http://www.cleane...ies.html As well as systems that sore renewables as hydrogen, or methane - http://www.gizmag...s/15007/

So much to be interested in - watching the picture unfold.
Waaalt
not rated yet Apr 01, 2014
An interesting approach and options are good because efficiency is often about picking the solution that is just right for a very particular job/niche/application/etc.

Still, how hard can it be to make small [gas] turbines to generate electricity on demand or nearly on demand, and then use that electricity to power an efficient electric motor to drive the vehicle?

and it would hinder the development of more green electric sources that would continue making the electric car more and more green.


This foolish, misguided notion is way too prevalent.

We do not need or want a bunch of dirty coal powered cars today so that we can maybe have "clean" all-electric cars eventually. Some techs may never pan out and yet in the mean time, research into them can still be subsidized.

What's better for the environment is relative to what is actually going on now. Incremental improvements that are real are far better than the insane pursuit of perfection.
Eikka
not rated yet Apr 03, 2014
so any time someone shows you a real world example of the success of renewables - you come up with a rationalization as to why that is not a good example.


First, what you showed was technically a dead link. I had to dig up google cache to read it.

Second, it was simply an advertizement piece saying "We've installed so much wind power" without going into any details how the system works or what they're doing to solve the problems.

Third, the Texan wind power system is a sham, just like the Danish system and the German system. They all work by pushing the power to someone else and have someone else deal with it so the wind power producers can get their subsidies.

You are aware right that demand curves for power are not flat lines right?


They largely are. Typically at least 50-60% of the demand is constant. The renewable power is not dispatchable and cannot reliably meet the daily variation, so it digs into the baseload where demand is always guaranteed.
Eikka
5 / 5 (1) Apr 03, 2014
But really. Let's take Denmark as a yardstick even though they "outsource" much of the pollution problems caused by intermittency to other countries.

The vast majority of EU nations produce more than 300 g/kWh in CO2, Denmark included, with the biggest offender Estonia making 1000g/kWh. The average of the EU-27 countries is 380 grams. Only a handful of small nations, and France, can limbo below the 300 gram bar, and France's secret is that 75% of their electricity is nuclear power.

An electric car like the Tesla S uses 380 Wh to the mile, which is 2.631 miles to the kWh. The EU-27 average emissions for electric cars today would therefore be more or less 144 g/mi, and 114g/mi in Denmark.

Meanwhile the average car in the UK already makes 142 g/mi and small hatchbacks and diesels routinely go around 90-100 g/mi. If you reduce these emissions by 30% you get 100g average and 70g minimum.

So the electric car has a lot of catching up to do before it makes any sense to call it clean
dvdrushton
1 / 5 (1) Apr 06, 2014
Eikka - all of your calculations add up to a great argument for why we need to get off fossil fuels. Take a look at the grams per Kwh of electricity break down by fuel source - http://en.wikiped..._sources

Do you have any up to date numbers on European countries and C02 generation? - I suspect your 2009 figures are very different today.
lengould100
not rated yet Apr 09, 2014
I'd just point out that IF you're going to use any gasoline internal combustion engine then an HCCI engine is about the most efficient engine cycle we know about. 18:1 compression is much lower than US govt. testing lab examples, which have run 35:1 in reciprocating electric generator engines. Might not make sense in a crank engine however.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.