Diesel exhaust fluid, or DEF, is a clear, colorless, non-hazardous liquid used to remove harmful emissions from diesel engines. DEF is composed of a combined solution of urea and water,

In 2010, the U.S. Environmental Protection Agency (EPA) required new emissions standards on medium and heavy-duty vehicles to reduce engine emissions – specifically NOx (nitrogen oxides) and particulate matter. DEF helps by breaking down NOx gases down into harmless water and gas using an advanced catalyst system. As a result, most of these vehicles have a DEF tank that must be refilled regularly. It’s important to note that DEF is not a fuel additive and is stored separately from the fuel tank.

Vehicles equipped with DEF can see benefits, such as optimized engine performance, better fuel efficiency, reduced maintenance and overall wear and tear on the engine, and reliability. It can even improve fuel mileage by as much as 5%.

Any vehicle or industry that relies on diesel engines must use commercial DEF fluid. It’s important to note that DEF isn’t offered everywhere – typically it’s offered in jugs at select stores and/or at the pump.

At Quarles Petroleum, we carry over 6 different types of fuel at select fueling stations – including DEF. We’ve served customers in our community with the most high quality fuel for over 80 years. Our associates can provide the best solutions based on your fuel needs – just visit our website at quarlesinc.com or call us at 877-444-3835 to learn more about how Quarles fleet fueling products can benefit you.