I have a 2000 Dodge quad cab Diesel 6wd. Dually. (Whew-say that 10 times fast) 5 Sp. with 4:10 gears. At 65 mph it's tack'in 2000 rpm and getting 18-21 mpg at 75 it's tack'in 2400 rpm and mpg is down to 15-16. I would suggest getting 3:54 gears as there is plenty of power and that would give you a better cruising rpm. I have 60,000 miles on her and would buy it again. I would prefer an auto on the next on. Hope this info helps. Rich.
