Good Answer Go Ducks !
I tow slower now that diesel is $ 4 bucks a gallon .
I set myself up to tow fast .
I use a 9200# gvw diesel on oversized michelin highway tires mounted on 8 inch wide wheels to improve handling .
I actually lowered my 4 x 4 hd 2500 to get better cornering .
I sold my bigger trailer to tow a 5300# 21 foot komfort .
I changed out my trailer tires to 106 mph rated LT tires in a bigger size to give me 9084 # of tire capacity to support the 5300 # .
I run 16 % tongue weight .
I still generally now cruise about 62-63 mph while towing .
But I have definitely gone 80 + when passing while towing .
Not often but I have done it .
Not even a hint of drama .
Before the flaming starts I also am an active sportscar guy with track and autocross experience .
I generally just go with the traffic .
But that does not mean that my modifications do not work in the real world on an unfamiliar curvy road at the end of the day when I get caught by surprise at that unexpected 35 mph switchback headed into that 7 % downgrade .