DEF Tank

Engines that are compliant with EPA10 and newer regulations are equipped with a DEF tank located either forward or behind the aftertreatment system (ATS). Other DEF tank locations are used if an inline ATS is installed on the vehicle. The DEF tank has a 19 mm filler neck inlet that prevents the hose from a diesel outlet from being inserted, and has a blue cap for easy identification.

The DEF tank will require filling a minimum of approximately every second diesel refuel depending on the DEF tank capacity. Shuttle Buses are equipped with a 13-gallon tank capacity. DEF consumption is approximately 2% of fuel consumption, dependent on vehicle operation. For every 50 gallons of diesel fuel consumed, approximately 1 gallon of DEF will be consumed.