MPH vs gear for climbing and descending hills 2006 chevy 6.0L vortec 4 speed with tow

[rvtime2]

do you have a table for downshifting by gear and speed for enging braking and for climbing.

yesterday at 7% grade in2nd gear water temp climbed to 235F at 55 mph and cooled down at 45-50 mph. I don't have a tach so need to use speed. I am towing a crv,combined wt about 16000 #. Our RV wt about 12500#
thanks

[CJBROWN]

You were climbing a 7% grade at 55mph with a toad?

If so I gotta say, that motor is putting out some ponies. I don't run my 8.1 past about 3500 and back it off in a lower gear that will maintain a steady pace up the grade. Some times that's 50-55, sometimes it's 40-45. We're actually kind of a light A at about 22K lbs. But yeah, a tach would help a lot. If you have a trained ear you can probly get pretty close to a guess.

Your auto trans is also heating up and likely to wear out fluid prematurely. Consider changing it at half the rec interval.

For downhills at 7-9% I'll run in 2nd or 3rd gear, 35-45, brake it back if it picks up speed. That way you're not on the brakes all the time. For shorter grades, 5-6% maybe 50-60 and then brake it back. Brakes can heat up and boil the fluid in the calipers and your brakes will completely go away. And rotors will warp and crack.