Tow/Haul - O/D lockout When & Where?

[Bob E.]

When we picked up our 03 Silverado in Colo. this summer the dealer said to use T/H when towing and O/D lockout when transmission temperatures get high. In purusing the posts on this subject there seems to be various reasons to use T/H, O/D lockout, or both. Comments would be appreciated!

[Jimamatic]

Bob E,
My 2001 did not come with the O/D lockout option
unfortunately. I'll have to pay to get it installed. Basically the lockout gives you better control between 4th and 5th gear. You can gear down to 4th without punching the pedal and will stay there as long as YOU want it to. What a beautiful thing. Given a constant speed, 4th
gear utilizes more H/P, burns more Fuel, and gives you a lower EGT. 5th gear gives you more
torque, burns less fuel, and runs a higher EGT.
At least that's the way I understand it. Enjoy
your 2003 O/D equipped truck...

Jim