Diesel engines can be more efficient than gasoline engines, but that's largely due to DEF. Here's what it does, how it helps, and what happens if you run out.

DEF stands for diesel exhaust fluid, and it is mandatory for all semi-trucks to use it in the United States. Here's why and what exactly it does.

Make sure to wipe away spills with a damp cloth, then close the DEF filler cap. Next, the video goes over what it takes to change the fuel filter on a GM vehicle equipped with a Duramax diesel engine.

The Environmental Protection Agency is changing regulations about diesel engines that could help Oklahoma farmers and truck ...

This change will let operators fix issues without their equipment shutting down, write the EPA's Lee Zeldin and the SBA's Kelly Loeffler.

You've surely heard of brake fluid, fuel, and lots of other liquids needed to run a diesel vehicle. But what's AdBlue fluid? And do all diesel vehicles need it?