Ive got a 05 silverado 4x4 5.7 letter gets 19 without and 13.5 with my 19ft ranger, I got the 4x4 not only for the winter but on steep ramps if wet I have seen pick ups that won't come up the ramp until you get 4 or so guys on the back bumper, I can go by myself and not think about it. My friend has a Dodge Ram with a comings diesel and he got a chip for the computer he pulls a 21ft bullet he puts it on cruse and I have seen it go up Hall's Gap and not down shift,he said after the chip he gets better fuel millage, I am going to try a chip for my chevy I have always had chevys but I must say that Dodge diesel is pretty impressive JMO

Gary