Petrol engines fitted to Mazdas in five years’ time will be significantly more fuel efficient than today’s

Mazda is aiming to lift the efficiency of its petrol engines by 50% by 2020, according to European research and development chief Kenichiro Saruwatari.

The current efficiency of its petrol engines is a competitive 40%, but it hopes to reach 60% in the next five years.

It hopes to do this by developing its homogeneous charge compression ignition technology (HCCI), in which the mixture is ignited by compression rather than a spark, like a diesel.

That will involve raising the compression ratio from about 14.0:1 today to 18.0:1 and achieving very precise control of the combustion process to avoid knock. The aim is to combine the cleaner emissions of a petrol engine with the efficiency of a diesel.

As part of its Skyactiv efficiency programme, Mazda is also investigating scope for reducing heat lost through the exhaust system, which typically loses about 30% of the fuel’s energy. “We’re looking at several solutions but can’t say which yet,” said Saruwatari.

The company has been pursuing its current efficiency path since the development of the 2002 Mazda 6, which was “generation one of the roadmap”, Saruwatari said.He said the next CX-5 crossover will be the first of the seventh generation. “The main direction of Skyactiv has not changed,” he added, “although we sometimes find new technologies and materials that produce a step change.”

Mazda recently announced a partnership with Toyota that could result in a plug-in hybrid model, but it has said its petrol cars could ultimately match EVs for well-to-wheel efficiency. This could mean average well-to-wheel CO2 emissions of about 80g/km for an unspecified ‘average’ model equipped with a Skyactiv Generation 2 engine.

The third generation of Skyactiv engines could take this even further. Mazda has previously spoken of average well-to-wheel emissions as low as 50g/km, although it has not set a date for this.

Get the latest car news, reviews and galleries from Autocar direct to your inbox every week. Enter your email address below:

Our Verdict

Mazda 3
The SkyActiv platform used in the 3 features more high and ultra-high-strength steel, offering greater strength and less weight

Mazda's SkyActiv revolution hits the family hatchback class

Join the debate

Comments
12

16 June 2015

Surely increasing compression is going to substantially increase temperatures (to over 1400 deg C) in the combustion chamber. The will enable nitrogen to oxidise to form various NOx emission as found in diesel engines? And presently NOx emissions are the new evil so is this a backward step? I guess is that petrol has a lower specific energy capacity so just maybe it does not get so hot in the cylinder. Anyone enlightened enough to know the answer?

16 June 2015

A quick look on Internet (articles.sae.org) brought up this piece of info, not sure whether this helps re NOx: "EGR systems divert some of the engine-out exhaust gas and mixes it back into the fresh intake air stream. Mixing exhaust with the intake air lowers combustion temperatures and rates. This improves emissions by reducing the formation of NOx. It also reduces the knock limit, providing better fuel economy through higher compression ratios and/or spark advance." There's another article on same site re Ford and Ecoboost: "Ford is aiming to squeeze another 25% brake thermal efficiency (BTE) out of its next-generation EcoBoost engines, using a combination of downspeeding, further downsizing, aggressive cooled EGR—and potentially using optimized stratified charge."

16 June 2015

Sounds like its going to need high octane fuels and be quite pricey to run.

16 June 2015

I thought diesels were 40% efficent and petrols are 25% efficient? 60% efficiency just from the engine sounds like a pipedream. They must be developing energy recapture systems.

16 June 2015

Even some of the more radical technologies currently used - such as direct injection, cylinder de-activation, Atkinson cycle etc - have only produced incremental gains rather than step changes. It's a pity that manufacturers don't quote their engines' thermal efficiency - I can only assume that the figures are so bad and so similar that there is not much incentive to do so. I suspect that all of the recent progress has been made on low speed part throttle performance in order to meet the current EU fuel test, and that basic thermal efficiency has not progressed much in decades.
Neverthless, I think Mazda has the right idea - in the short term it is far better to introduce millions of improved i/c engines (in lighter cars), rather than a few tens of fuel cell vehicles, or a few thousand electric ones.

16 June 2015

"petrol cars could ultimately match EV" no chance. The Leaf costs less than 2p a mile, with petrol you'll be lucky to get 12p therfore petrol cars would need around 300mpg. Good luck with that. If you've got solar panels already and start to use them to charge the car the difference is even greater.
As to sparkless cars - Honda had a sparkless 2 stroke in the Dakar rally ages ago, but they never really progressed it.

 

Hydrogen cars just went POP

16 June 2015

SKY_INACTIVE is nothing, they say things like we've made it light, used specially shaped pistons and 4-2-1 exhausts. This things mean nothing, are they trying to make out BMW use randon shaped pistons made of lead! Anyhow sky-inactive is just a fancy name meaning they've got no small turbo engine for common use or a plug-in option.

 

Hydrogen cars just went POP

16 June 2015

Wow...all these online armchair development engineers! Miserable naysayers.
Do you really think a company makes these claims without having done years, yes years of development?
Christ on a bike.

16 June 2015

Armchair development engineers - I like it. Well I can change a tyre so I'm not qualified to comment on the engineering proficiency of the internal combustion engine but I do have experience of buying and running a variety of cars over many years and I'll say Mazda is talking bollocks (my engineering terminology). I currently own two cars with a list of fuel saving devices as long as your arm, neither car comes near to achieving the mpg figures of their direct predecessors. Explain that. And when looking for a cheap to run family petrol saloon in 1995 after having been used to a company diesel for three years, I bought a 1.6 Toyota Carina E. Average mpg was around 43mpg. 20 years later, whats the real-world mpg from a smaller 1.0 3 cylinder award winning Ecoboost Focus that replaced their 1.6 that struggled to see 40mpg? Worse than that 20 year old Carina! There's no doubt technology has brought us cleaner and more efficient / powerful engines, but when claims are made they bring more 50% more mpg... I'd hazard a guess the information is coming from Mazda sales and marketing rather than their engineering development dept.

16 June 2015
michael knight wrote:

Wow...all these online armchair development engineers! Miserable naysayers.
Do you really think a company makes these claims without having done years, yes years of development?
Christ on a bike.

I think we would all be more believing if other manufacturers made similar claims. For instance, VW, who show innovation through their products like the XL1 and E Golf are aiming by 2020 to have a fleet average of 95g/km across its range as per EU directives. It is finding even this difficult. For a much smaller firm with a much smaller R&D budget like Mazda who has shown no technologically experimental vehicles, nor even has a hybrid in its line up, for them to blow VW out of the water with 60% efficient petrol engines. Please. Its like the new college grad who huffs and puffs about being an entreprenerial millionaire by the time they are 30, the evidence being the 2:2 they got on their business degree.

Pages

Add your comment

Log in or register to post comments

Find an Autocar car review

Driven this week

  •  Kia Optima PHEV
    First Drive
    25 August 2016
    Plug-in hybrid Optima is a practical, tax-efficient PHEV that undercuts rivals and fulfils its main remit well, but keen drivers need not apply
  • Kia Optima Sportwagon
    First Drive
    25 August 2016
    New Kia estate looks the part, has good space and handles tidily, but its engine's flexibility and refinement let it down
  • Lamborghini Huracán LP610-4 Spyder
    First Drive
    24 August 2016
    Awful driving position aside, drop-top Huracán handles UK roads well. It's more dynamically rounded than its rangemates, but lacks rivals' handling bite
  • Porsche Panamera 4S Diesel
    First Drive
    23 August 2016
    Its predecessor may have been a bit limp, but the Porsche Panamera 4S Diesel is crushingly rapid and suitably luxurious
  • Car review
    23 August 2016
    Can the best sports coupé of the decade absorb a contentious new engine?