Originally Posted by need-a-vacation
I have the same thought concerning the higher rated speed vs the old 65mph rating. The more margin there is, the better. Same as buying the next higher load range tire for more of a cushion for the max weight rating.
Have you weighed your tt? If so, how much does it weigh, and what tires do you currently have? Are you using the total trailer weight, or just the actual axle weight when hooked up when you figured the margin?
Yes I have weighed the rig, but that was 1 year or so ago and I know our loading habits have changed.
I was at 16,040 lbs total with 7060 lbs on the trailer axles.
Trailer GVWR = 8500 lb
Axle GAWR = 4400 lbs x 2 - 8800 lb
Tires are Tow Max ST225/75R15's LR? (2530 lb @ 65 psi)....The picture I took of my tires cut off the LR rating
I think they are D's
Total Tire load = 2530 x 4 = 10,120 lbs
8500 lb GVWR with 12% on the tongue
8500 lb - 1020 lb = 7480 lb
10,120 lb - 7480 lb = 2640 lb Margin
So I am assuming the margin is while towing with some weight on the tongue.
When I weighted the trailer last year, I had even more margin with the Trailer axles only taking 7000 lb. I did not take the other 2 measurements to see what the tongue weight was....never to seem to get off in time to afford a stop at the CAT scales!
I try to keep the trailer at about 62, but don't mind too much if I gain some gas mileage freewheeling down hills at a little higher speed as long as there are no curves and I don't gain too much speed (the higher gear lockout button on my F250 works great for downshifting and maintaining speeds on hills)
Driving 4300 miles out west it would have been nice to push the speed up a little on the long flat drives on the plains, but agree to keeping things safe with the Family on board.