robert78.5

I was always told to keep it in overdrive unless it kicks down more than 2 times in a mile. This is on the prairies. When in the hills you should lock it out.

CamperAndy

TH on the 06 48re does not lock out the OD. It changes the shift points and hold the torque converter in longer. It will improve your mpg and lower your transmission temps if you do much 35 to 50 mph driving as the transmission is driving the truck not just spinning fluid around.

I use it all the time, towing or not.

Bob T

I run T/H all the time with the e-brake . I find it a comfortable way to slow without constantly swapping pedals. Around town I use 4th gear and it serves well for my particular driving style(unhurried) . The biggest drawback is the un-alert tail gater. I've had a number of inattentive drivers almost get friendly with my receiver hitch, since I don't apply brakes until I have to.

aborgardt

x2, like 30* lower. More power to the wheels to.

boaterman

x# -- All the time... I get about 1/2 mpg less fuel mileage.