Bulk Diesel Exhaust Fluid Supplier (DEF)


With the largest network of diesel exhaust fuel dispensers in the Mid-Atlantic, Quarles is here to make sure your fleet never runs out of DEF.

We offer convenient bulk DEF fueling options to suit the needs of any fleet operation:

• Buy at the pump at most Quarles Fleet Fuel sites near you.

• Take advantage of our bulk delivery service and let us bring DEF to you.

When you use Quarles for your DEF fleet fueling needs, you can be confident you’re receiving the highest quality fluid handled with care from an experienced and reliable provider. Take a look at the product data sheets for Blue Sky and Brenntag for more details on the DEF brands we carry.

What is DEF?

DEF — Diesel Exhaust Fluid — has been heavily used in the US since 2010 when EPA legislation was passed to improve the emissions requirements for diesel vehicles. Specifically, the goal was to reduce the nitrides of oxygen (NOx) from being emitted.

As a result, diesel trucks of model year 2010 and newer have a selective catalytic reduction system that injects DEF which is then vaporized before passing through the catalytic converter. This converter is built from two sections specifically designed to remove the NOx gas from emissions.

Diesel Exhaust Fluid is made from around 32% urea and 67% de-ionized water. In chemistry terms, the urea in DEF fuel turns into ammonia when vaporized and heated. When this comes in contact with the nitrous oxides, it becomes nitrogen and oxygen which are both harmless to the environment.

Unfortunately, DEF tank refills are not optional. Running out of Diesel Exhaust Fluid is just as bad as running out of diesel fuel because regulations also have measures put in place for trucks to limit trucks to 5mph once there is no more DEF in the tank. Thankfully, there is a series of warning lights to alert the driver that DEF is getting low.

How Much does DEF Cost?

Just like standard diesel fuel, Diesel Exhaust Fluid bulk prices can vary based on your location and availability. Quarles helps you save by offering DEF delivered in bulk and by conveniently placing DEF tanks at our many fueling stations.