Multiple improvements combine to improve efficiency of the Skyactiv gasoline engine

Published: May 2, 2012, 7:00 AM

Mazda SKYACTIV-G engine

It's not always easy to find consensus among the different players in the auto industry. But representatives from Chrysler, Ford, General Motors and Toyota who participated in a panel discussion on “2018 and Beyond Powertrains” at the 2012 SAE World Congress in Detroit, last week, all agreed on one thing.

That is, the gasoline internal-combustion engine (ICE) will continue to be the dominant automotive powerplant for the foreseeable future.

Unless there is some significant breakthrough in electric vehicle technology, reducing cost and extending range, ICEs are still expected to dominate for at least the next 20 years, they suggest.

Mazda agrees with that assessment. So strongly that the company is, in effect, betting all its marbles on the IC engine.

Mazda is focusing all its powertrain engineering resources on maximizing the efficiency of the ICE, rather than diluting them to also pursue hybrid, electric, and fuel-cell strategies as most other automakers are doing.

At the core of the company's overall Skyactiv concept is "going back to basics." And that is precisely what Mazda's engineers have done with the design of the Skyactiv G (G for gasoline) engine.

They with started with a clean sheet of paper (or perhaps I should say a blank computer screen) with a major focus on the combustion process itself, raising the compression ration as high as possible while  achieving stable, complete combustion without knocking. 

Minute attention to detail enabled an increase in compression ratio to 13:1 (12:1 in North America to accommodate our fuel characteristics). 

Then they attacked all the areas of engine design that caused power to be lost before it got to the output shaft and reduced them as well.

The net results are approximately 15-percent lower fuel consumption and CO2 emissions and 15-percent more torque at low and mid-range speeds.

Perhaps the best and most concise explanation of what they did can be found in a short video produced by Mazda. Check it out at