"With the internal braking system similar to the BANKS system, it pulls a 22,000 lb 5th wheel with ease even up or down a 6% grade. Diesel is silent. milage is 12 pulling a 5th wheel. All eyes follow and mouth opens when this truck goes by. (2008 came out in 2007 to correct tow problem) The 4wheel drive is awesome. Heating and cooling is instant."