Stopping to refuel a large sport truck can be a hassle, especially when you are towing a long trailer or car hauler. Even with an efficient diesel powerplant between the framerails, today's trucks just don't offer the fuel capacity to go more than 500 miles on a tank of fuel, and that is a real hindrance when you're eastbound and down, loaded up and truckin'. The solution is simple: Install an auxiliary fuel tank in the bed of your truck. But, what if you just can't give up that precious cargo space within the bed? What do you do then? You call the guys at Transfer Flow and order up one of the factory replacement tanks.
The owner of this GMC Sierra Crew Cab dualie regularly hauls a 38-foot race trailer with an NHRA A-fuel dragster inside and all of the pit supplies needed to go racing. Although his truck touts a stout Duramax diesel engine with enough grunt to pull the trailer, towing from California to far-off racing destinations meant making a lot of necessary stops for fuel, which wasted precious time. We outfitted his dualie with a new tank from Transfer Flow, increasing his truck's fuel capacity from 33 to 56 gallons, in a matter of hours. After the install, he was able to drive more than 800 miles on a single tank of fuel. Now that's a long haul. Transfer Flow offers tanks for several makes and models of sport trucks with both gas and diesel engines. Here's how the installation went down.
 What's In The Box? Transfer...  What's In The Box?
Transfer Flow includes everything but the tools to install its new replacement tank. The factory fuel pump and sending unit will be retained and reinstalled into the powdercoated tank, as well. |  1. The installation began...  1. The installation began by unhooking the factory fuel-filler neck from the bed side. There are four 8mm bolts that can be removed using a socket wrench or, in our case, a socket attached to a drill motor. |  2. Next, the ground strap...  2. Next, the ground strap needed to be removed from the chassis by removing the 10mm bolt, using a box wrench. |
 3. Transfer Flow even includes...  3. Transfer Flow even includes this cool plastic tool that is needed to disconnect the factory fuel lines from the in-tank fuel pump. The tool slides into the fitting to spread the spring-loaded fingers apart, and the line just pulls apart. |  4. Once the fuel lines were...  4. Once the fuel lines were disconnected and the fuel-filler neck was out of the way, the plastic tank shield was removed and the fuel tank straps were unbolted. The tank was the gently lowered out from beneath the chassis. |  5. To remove the in-tank...  5. To remove the in-tank fuel pump from the stock gas tank, this retaining ring needed to be depressed and then rotated 30 degrees around the pump. It's best to have an extra set of hands to perform this procedure. |
 |  6. As you can see, the new...  6. As you can see, the new tank is substantially longer than the factory unit. Most of the extra capacity comes via added length at the rear of the tank as well as the top. |  |