Auxilliary fuel tank


New Member
I want to add on about 20 gals. of fuel capacity to my 2500 HD Silverado. Anybody have any advice on combo tool box and fuel tanks or stand alone bed mounted tanks??? :laugh:
Auxilliary fuel tank

Check out: for replacement tanks (45gal SB, 56gal LB).

I have a 41gal fuel/tool box combo (67 gal total) from Northern Tool that was $500. But to be DOT legal and not void warranty, the 2nd tank needed a 2nd GM fuel pump, 6-port valve, vapor vent, hoses, etc that cost $700. Replacement tanks were not available when I did my install. You can see pics at:
I removed the tool box lid since with a rubber gasket, my folding cover fits flush anyway. With 11.3 mpg towing, I can easily go over 650 miles without refueling. Recently spent 10 days in Canada w/o having to pay Canadian prices.