Titan Fuel Tanks 4030213 Spare Tire Auxiliary Fuel System30 Gallon innovative Spare Tire Auxiliary Fuel System for 2500 & 3500 DODGE Pickup Models with Cummins Engines. (For model years 2013-2014)TITAN's Spare Tire Auxiliary Fuel System (STAFS) puts an additional 30 gallons of fuel at your fingertips. In most cases this doubles the fuel capacity of American-made diesel pickup trucks made after 1999. This innovative system is designed to repurpose the space commonly used to stow a vehicle's spare tire. This product ships in approximately 1 days