'04 chevy silverado 5.3l v8, I need to tow my boat about 15 or so miles, ive never towed it this far as the launch is right down the road never getting over 30mph, ive always used the "trailer" or "tow" function that is engaged by pressing the button at the end of the shifter... Now I need to tow the boat 15 or 20 miles soon on the highway where ill be going around 45 mph... so my question is should I use the tow button at these speeds? To be honest im not entirely sure what all the tow function does, although ive read something about it not changing gears as fast? Pr some thing.. . Any ideas or suggestions? I sure dont wanna burn up my trans... Boat is a 1976 glastron gt-150 with a 1978 85 hp johnson, if that matters and the truck has always pulled and stopped it fine... Thanks in advance!