I tow my 10k pound boat with my tahoe all summer. Granted the tahoe is rated for 8k but...I push things over the limit alot haha. Granted I do have the HD towing package..But in the south texas heat, I'll take all the cooling I can get. The tranny cooler extends the transmission's life greatly in the heat. She struggled a little in the hill country but just when you arrive, make sure you don't just cut the engine off...make sure you let it idle for a little while to let itself cool off. The second you turn off the engine, that is when your cooling stops to it. I also have 241k miles on er, original tranny and only one flush done to her...may be time for it again too