Diesel Exhaust Fluid

Reduce emissions and keep your diesel vehicle running clean with diesel exhaust fluid (DEF) from AutoZone. We sell the best brands, including AutoZone, Lumax, and Peak Blue DEF fluid. We also sell accessories, like a DEF pump, nozzle, flow meter, or coupler. Get free next day delivery when you buy your fluid or parts online or pick up what you need today at an AutoZone near you.

AutoZone has everything you need to top off your diesel exhaust fluid tank. Need 2.5 gallons? Pick up one AutoZone brand single-use bottle. Need a little more? Get a barrel that's right a whole barrel containing up to 330 gallons of Peak BlueDEF diesel exhaust fluid. We have DEF in any quantity you need.

We also carry everything you need to get the fluid in your vehicle. With our collection of Lumax and Peak diaphragm pumps, flow meters, and dispense couplers, we have everything you need to set up your own DEF pumping station, complete with an automatic shut-off nozzle just like they have at the gas station. If you're setting up your own station at home, get a complete motorized diesel exhaust fluid pump that you can easily mount on a barrel.

Diesel exhaust fluid is used by Selective Catalytic Reduction (SCR) technology in diesel vehicles' emission systems to reduce Nitrogen Oxide (NOx) and particulate matter (PM). SCR systems on diesel vehicles use DEF to cause a chemical reaction in the catalytic converter in which NOx reacts with the ammonia in the fluid, leading to a near-total reduction of NOx and PM emissions, and a slight boost to fuel economy.

Drive efficiently and responsibly with a full DEF tank. With our selection of diesel exhaust fluids, pumps, parts, and more, AutoZone makes it easy to boost fuel economy, while keeping your emissions low.