DEF at the pump.
Not in a box.
Bulk DEF at a fuel island costs roughly a third of what you pay for a jug — and it's easier, cleaner, and fresher.
What is DEF?
Diesel Exhaust Fluid (DEF) is a non-hazardous solution of 32.5% urea and 67.5% deionized water. It's injected into the exhaust stream of diesel engines equipped with Selective Catalytic Reduction (SCR) systems, converting harmful NOx emissions into harmless nitrogen gas and water vapor. Most 2010-and-newer diesel trucks, RVs, boats, and equipment require it to run.
Why pump over jug?
Bulk DEF at a truck stop runs $2.50–$3.50/gal. Boxed DEF at Walmart or AutoZone runs $9–14/gal. On a 10-gallon fill, that's $60–90 in savings.
Bulk DEF at a busy truck stop turns over fast. Jugs on a shelf may have sat for months — DEF degrades in UV light and heat.
Fill at the same pump as your diesel. No lifting jugs, no funnel, no spilled fluid.
You can fill exactly as much as you need. No partial jugs to store.
Major chain dispensers are typically ISO 22241-compliant — the same standard truck fleets require.
Who needs DEF?
Any diesel vehicle with an SCR system — which includes most 2010+ diesel pickups (Ford Power Stroke, Chevy/GMC Duramax, Ram Cummins), Class A and Class B diesel RVs, diesel-powered boats and yachts, and farm and construction equipment. If you see a blue cap on your fluid reservoir, you use DEF.
Pump DEF is faster, cheaper, and fresher than jug DEF. The only challenge is finding a working dispenser in a lane your rig fits. That's exactly what this site is for.
Find a pump near you →