You may have heard your car has a four-stroke engine, but you're not sure what that means. Why are there four? And what is a stroke, anyway? A modern gas engine most commonly uses pistons and a ...

The German automaker sees your four-stroke engine and raises you... two more strokes. Ready for some math? Porsche just ...

In the exhaust stroke, the exhaust valve is open and the combustion products are expelled from the cylinder. The sequence shown on the next page represents this behavior for a Mitsubishi direct ...