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.

All of these will have DEF tanks and SCR systems. Where DEF really becomes critical is in big diesel engines. We don't mean like your Cummins 6BT, we're talking Class 8 semi-trucks.

In 2014, the EPA revised its guidelines on DEF to include DEF refill intervals. Depending on the type of diesel vehicle you own, you may need to refill your DEF tank every 4,000 miles, at a minimum.

The DEF tank on a vehicle has a heating element that will quickly thaw the liquid and it will continue to be on spec’ after thawing. “Like water, DEF will expand up to 7% when frozen and can damage a ...

Diesel exhaust fluid, also known as DEF, AUS (from aqueous urea solution), or AdBlue, is used to lower the concentration of NOx in diesel exhaust emissions.Usually, the DEF tank filler is placed ...

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.