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DEF Trucks

A DEF truck from Osco Tank and Truck Sales featuring a blue Mack truck cab with a stainless steel grill. The truck has a stainless steel round tank.

What are DEF Trucks?

DEF stands for “Diesel Exhaust Fluid.” It’s a system that helps convert nitrogen oxide (a dangerous emission) into harmless nitrogen and water. As a result, DEF trucks help reduce smog, acid rain and air pollution.

On a DEF truck, the Diesel Exhaust Fluid is stored in a separate, insulated tank that typically has a blue cap. Diesel Exhaust Fluid is non-toxic and non corrosive.

How Does DEF Work?

The fluid is sprayed into the exhaust steam of diesel vehicles to break down the nitrogen oxide. DEF is not a fuel additive and never comes in contact with diesel.

A Diesel Exhaust Fluid system does require a bit more room in your truck and adds slightly to the vehicle’s overall weight.

However, DEF trucks are designed for better fuel efficiency, more optimized combustion and increased power. The EPA requires all vehicles capable of running with Diesel Exhaust Fluid do so.