i tow a 24' enclosed carson race car hauler. loaded was 6500-ish and i have more gear coming... total guestimated weight should be about 7500... at 6500ish, i was towing at 75-80 with no issues on the flat straight parts. out here, up the grape vine in california, i was able to go up 60-ish while deisel tow rigs were pushing 35... be sure to have an anti-sway system and brake controller that is up to the task. i use 10,000lbs anti-sway hitch with a tenkonsha prodigy controller = no sway what so ever.

widthl should have some more insight to share. he's towed close to 9800 lbs..