Rotary engines differ from conventional ones in many respects — and one of them is the fact that they use two different spark plugs. Here's why.

Pop the hood on a classic Mazda RX-7 or RX-8 and the engine bay looks oddly empty. That is the charm of the rotary engine: a compact lump of metal that trades pistons and valves for a spinning ...

Perfectly tuning the heat range of an engine's spark plugs is something of a dark art to all but the most well versed tuners and the engineering egg heads at automotive OEMs. Getting the spark plug ...

The rotary was the most radical rethink of the combustion engine in over a hundred years — and it paid the price for being different. Mazda introduced the innovative Wankel rotary engine in the 1967 ...

In a world dominated by pistons, the rotary engine was something different for motorists. It was the vision of German engineer Felix Wankel, built on the belief that the up-and-down motion of pistons ...