Brown Oil is a distributor for PEAK Diesel Exhaust Fluid. Peak is the purest possible end-to-end diesel exhaust fluid. Making sure you don’t run out of DEF is simple, partner with Brown Oil. Our closed liquid dispensing systems from supply points to your tank ensure you have nothing but the highest quality DEF. We offer DEF in 2.5 gallon jugs, 55 gallon drums, 330 gallon totes, and larger bulk applications. We carry a full line of DEF equipment and are skilled enough to install custom tank and pump set ups.