Researchers aim to meld the best attributes of both the power-dense two-stroke and the vastly cleaner four-stroke engines.

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

I can never resist a good oddball engine, and this one’s pedigree is impressive. See if you can bend your mind around it. Most of you reading this probably have at least a basic understanding of how ...