I no most aren't rated for more then that it doesn't bother me to tow that fast used to drive for a livein
So, if you drive for a living then you should know. (Not sure about spellin though.)
Typical trailer speed rating. Not to drive at that speed while towing. Yes, you might be comfortable, what about the others on the road... Stopping, changing lane, you blowing around, trailer wagging etc. Your truck was telling you, 'hey this isn't the speed you really want.' Were you using the Tow/Haul truck setting?
Also, I get you saying what gear it wasn't changing. You should tow w/o overdrive, for me that's 7th gear.
Slight road incline, wind speed, tire ratings (both trailer & truck). Were all tires inflated to the proper towing psi; max psi? Did you load the trailer the right way? How much weight was in your truck? People, snacks, lead foot...
So, maybe next time you'll put others in mind when towing. Maybe, take care of your truck too. Yup, the truck can handle the rating - NOT at 80mph. What speed these days do you see 18 wheelers driving?
I'll also bet, you might rethink posting this type of question. You can get mad at me pointing all this out... Dude, slow down just a bit, and what are the rules of the road?
Omg and tell me what part of the world you live. I want my family far away from you. Adding a programmer isn't the fix.
Be a courteous driver - Shower Traffic Keep Right.