I have a 2016 GMC Sierra 6.2. I tow my RV (around
1650 of) for 5 to 6 hours twice a month.
Is it better I drive the car with the tow mode on or
off? What is better for the car!
When towing or hauling a heavy load use the tow mode. In normal driving turn it off. Refer to the owner's manual for more information.
Bob is right, when towing use tow mode. It changes the shift pattern of the transmission so that the tranny doesn't work so hard.
The tow mode will help keep the transmission cooler and a cool transmission is a happy transmission. Heat is the enemy of transmissions.