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 ...

For most diesel-powered engines, DEF is vital so the vehicle performs at its best. Here's what it is exactly and what the ...

Diesel Exhaust Fluid is not already added to diesel fuel ... reducing by an estimated 90% the harmful emissions of diesel ...

Easily Clean the Entire SCR DEF System Under certain conditions, the water in DEF can evaporate, leaving behind white crystal ...

Freezing does not change the effectiveness of the fluid. The ideal storage ... Too much idling of new emissions compliant machines can build up soot in their diesel particulate filters, requiring ...

You'll need to add diesel emissions fluid periodically, but it's easily done through a filler port next to the fuel filler and usually costs only about $6 per gallon at auto-parts stores.