The rotary engine has been absent on the frontline for quite some time, and it's on the way back. But not with Mazda.

Rotary engines (also known as Wankel engines and Wankel rotary engines) are quite different from piston or "reciprocating" engines. One of the distinguishing features is that they don't need valves to ...

You'd think measuring an engine's displacement would be simple, but there's a long history of trying to figure out how to categorize the Wankel.