For truck buyers who need to tow more than your average truck, there is the 2500HD heavy-duty version of the Silverado that are available with a 397hp 6.6-liter Duramax diesel engine. The mighty 2500hd can tow up to 17,800 lbs. When not towing, the 6.6 duramax combined with 36 gallon fuel tank and 6 speed Allison Transmission can yield you 680 miles!!! That’s pushing 19 miles to the gallon!!! Not bad for an almost 7000lb truck! An available smart exhaust brake provides greater control on downward grades and reduced brake pad wear. Others may boast that their technology far exceeds that of the ever dependable Chevy… I say “I want a truck that works for me… Not one I need to learn how to workâ€