The Titan Tank 4030203 is an auxiliary fuel system that is mounted under the bed where the spare tire is kept. It's one of the only auxiliary fuel systems that have zero impact on the hauling capacity of your truck. 

The STAFS™ military grade cross-linked polyethylene tank body is light at only 30-pounds, making it easy for one person to handle, and includes mounting hardware, a filler kit, and an electronic fuel transfer monitor and control unit which is operated from the comfort of the cab. The electronic system gives the vehicle operator total flexibility in managing how the extra fuel capacity is used.

The fuel can be held in reserve or transferred on-the-go as the need arises. The controller’s illuminated user interface indicates the tank’s fuel level and features a single-touch button that starts the fuel transfer sequence. With one touch, fuel begins transferring from the STAFS™ tank to the vehicle’s primary fuel tank and continues to flow until it is automatically stopped by the controller or the button is touched again.