Overdrives work great as long as the ground is flat and the load is light (ie. not towing or empty PU bed) otherwise the mechanical effiency drops and can cost you fuel mileage. If you are in favor of better fuel mileage raise your right foot and keep the RPM's in the 1800-2200 range.
It seems he (snowman)is turning 3000 RPM keeping up w/traffic.
OD, gears have more uses than just going flat level ground or needing to be light on your load to use OD.
MBHD
