Engine/Transmission Temperatures While Towing Up Grade

[jamoody]

I'm taking my 2017 Yukon cross country and through the Rocky Mountains towing 3600 pound camper. I installed an external transmission cooler and understand that normal operating temperature is 200 with 10 min peaks of 225 up a long hill being acceptable. Normal engine operating temperature is 210 and expect the temperature to rise in the mountains, but what would be considered the acceptable peak engine temp?

Thanks.

 

[k-mart]

Posted this in another thread about towing MPG. I don't know the exact weight of my trailer other than it is 2200lbs unloaded and we had it filled up. I never even paid attention to oil temps. Towing is much rougher on the trans than the engine.

Late last month, I towed a 7X16 cargo trailer completely full of totes/toys/general houseware from central NC to Colorado Springs. Went up thru VA then to Nashville then up thru STL and headed west thru Missouri and Kansas. Quite a bit of elevation climb. I saw an even 10.0mpg according to the DIC. I didn't bother to calculate the true MPG since I didn't want to be even more depressed. I'd assume it's at least 1mpg optimistic. Still was a great tow vehicle and I never once felt like the rig was being worked very hard. The highest trans temp I saw was 207 but I'd forgotten to turn on tow/haul and it dropped back around 200 pretty quickly. So no real issues with temps for me.

2015 Yukon XL
-Max towing package
-Airaid Jr.
-Black Bear Tune
-Weight distributing hitch with sway control