How often do you put DEF in a diesel truck?
If you've recently made the switch to a modern rig, you're likely wondering how often do you put DEF in a diesel truck to keep it running smoothly. The short answer is that most drivers find themselves refilling the Diesel Exhaust Fluid (DEF) tank every 3,000 to 5,000 miles, but that's not a hard-and-fast rule. It really depends on how you drive, what you're hauling, and even the weather outside. ...