Why Mazda Loves the Rotary Engine
Wankel engine development began in the 1920s by German inventor Felix Wankel. Eventually Wankel would collaborate with German car and motorcycle manufacturer NSU in the 1950s to make the rotary engine suitable for use in a motor vehicle. Despite the numerous advantages of the rotary engine over the Otto 4-stroke piston engine, there is only one major automaker that continues to support development of the rotary engine — Mazda.
The primary advantages of a Wankel engine are size, simplicity, and smoothness. There are only three moving parts in the engine compared to dozens or more in a piston engine, this lends itself to being more reliable and durable than a piston engine. Because there are no reciprocating parts — like pistons and connecting rods — the Wankel engine has little vibration. Accounting for the smaller size and lighter weight of a rotary engine, it indirectly improves handling because it can be mounted lower and closer to mid-ship.
“Most people don’t realize the numerous advantages the rotary engine offers over a standard 4-stroke engine,” explains Frank Mitchell, Manager and Director of MazdaPartsUSA.com. “Dare I say it, but rotary engines are in many ways the best engine option available,” says Mitchell.
If the Wankel engine is so good, why was Mazda the only major carmaker to produce cars with rotary engines? The answer lies with the demanding CAFÉ standards for better fuel economy and less noxious emissions. Rotary engines are thirsty buggers when driven at high rpms, and CO2 and unburned hydrocarbon emissions are higher than a piston engine.
Mazda hasn’t given up on the rotary engine despite its challenges. There is hope that the company’s SKYACTIV technologies might work out a solution to the problems. Once that happens, watch for Mazda to announce a new RX-9 with a twin-turbo SKYACTIV rotary engine.