Toyota To Buck Engine Downsizing Trend, May Go Larger And Turbo - Free



Toyota to buck engine downsizing trend, may go larger and turbo-freeKoei Saga, a Toyota senior managing officer in charge of drivetrain research and development, says that eschewing turbos and increasing displacement of engines using the Atkinson cycle can produce better power gains without sacrificing fuel economy.




Toyota is investing heavily in larger-displacement Atkinson-cycle engines in addition to turbocharged engines, but Saga doesn't think the automaker will use turbocharging across many product lines. He apparently remains unconvinced that the technology "makes the world better."

In Toyota's eyes then, Atkinson cycle engines do make the world better, and here's how. By keeping the intake valves open longer, they effectively reduce the length of the compression stroke, cutting pumping losses. The result is greater efficiency at the expense of some torque. This works really well when paired with a hybrid system where the electric motor can provide plenty of torque from very low rpm. Even in a non-hybrid a larger-displacement Atkinson cycle engine could produce a net benefit in efficiency while restoring the torque and power without the weight and cost of the hybrid.