i just installed a 6.0 trans cooler with a autometer trans temp gauge. (i should have installed the gauge first to compare before and afters). we just went from long island to niagara falls and back towing a 9500lbs camper. about 17,500lbs gross combo. going there the temp gauge never went over 152 degrees on the way back it reached 170 degrees we took a fdifferent way home. i'm more than happy with both upgrades...would reccommend them to anyone. just wish i knew my temps before i installed the cooler. (1300 mile roundtrip)