EPA demands DEF failure data from diesel makers. Investigation could force recalls and software fixes for engines already on U.S. roads. 30-day deadline set.

Let's face it, most engine additives don't really improve performances. If you want to try one that does, here's what you should pick.

Even if you don't plan on ever owning a car with a diesel engine, you may still want to know how they compare to gas engines ...

Keeping the engine bay clean is not just a matter of cosmetic appeal; it is a significant aspect of vehicle maintenance that ...