Mazda has never been afraid of some truly odd engine designs. It keeps trying to make the Wankel work. It has a gas engine with compression ignition. And the company has made 14:1 compression gas ...

Combustion engines with an odd number of cylinders are not unheard of but are not particularly common, either. Honda‘s just trotted out an interesting one: A V3, so, two pistons on one side and one on ...