Mazda is clearly not giving up on developing new internal-combustion engines just yet. The Japanese automaker is saying it hopes its third-generation Skyactiv engine technology will make its gas engines just as efficient as battery-electric vehicles.
The claim is a bold one, but reasonable after diving into the details. Mazda says the primary goal with Skyactiv-3 (what they’re calling the third-generation engine) is to increase the engine’s thermal efficiency. The vast majority of energy created by internal-combustion engines is lost through heat it generates, versus torque it sends to the vehicle’s wheels.
Right now most gas engines average around 20 percent thermal efficiency. Mazda is hoping to boost the thermal efficiency of the Skyactiv-3 engine to about 56 percent, which would push the engine significantly above diesel engines, which are generally around 40 percent efficient.
Mazda isn’t detailing how they will go about increasing thermal efficiency in the engine. It’s expected they will use their upcoming Skyactiv-X engine as a basis. Rolling out in 2019, the Skyactiv-X engine features Spark Controlled Compression Ignition, giving it efficiency on-par with a diesel engine without the added emissions.
Mazda’s powertrain chief, Mitsuo Hitomi, recently detailed the company’s plans for the Skyactiv-3 engine to Automotive News citing a hope of increasing emissions by about 25 percent over the Skyactiv-X engine.
An increase in emissions by 25 percent would put the Skyactiv-3 engine on-par with the overall emissions of many battery-electric vehicles. How so? When how the electricity is being generated (coal, natural gas, etc.) is factored into the overall emissions of electric vehicles, they too pollute.
Hitomi declined to offer a timeline as to when we can expect the Skyactiv-3 engine. Nonetheless, it sounds as if Mazda is far from giving up on innovating the internal-combustion engine.