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

For more than a decade the name Wankel has popped up whenever car enthusiasts start talking about advanced-design automotive powerplants. The theory of the Wankel engine goes back to 1954 when Dr.

We look at why Mazda introduced the three-rotor 20B Wankel rotary engine, and why it only ever saw service in the Cosmo coupe of the late 1980s.