JIMNLIN wrote:
mikeup wrote:
BTW, tires do little. LT tires will stiffen the side walls of the tire so that the handling is better. BUT standard P tires have more than enough capacity for the truck. Most larger P tires are rated for 2500 to 2600 lbs. X4 = 10,000 lbs!!! More than enough tire capacity out of a P-tire.
According to fed regs ;
"When a passenger car tire is installed on a multipurpose passenger vehicle, truck, bus, or trailer, the tire's load rating shall be reduced by dividing by 1.10 before calculating the sum (i.e., the sum of the load ratings of the tires on each axle, when the tires' load carrying capacity at the recommended tire cold inflation pressure is reduced by dividing by 1.10, must be appropriate for the GAWR)."
Doing the math show the P tire still has enough capacity but not as much reserve.
I had always heard that P tires get derated when used on trucks. While a truck can still be well within capacity with a P tire, there are significant performance advantages to an LT tire. Notably the sidewall stiffness of LT tires. Even without towing I can feel P tires mush sideways during a turn. Towing a even a 5k landscape trailer just feels worse on P tires... IMHO, YMMV.
Back to the OP marginal weight issues, the correct answer is to stay within weight limits. That said, with properly maintained equipment (including TT brakes / hitch) and conservative operation I would not sweat your numbers. I would put an after market diffy cover with cooling fins on, and maybe the trans pan. Fords call for 75w140 in the rear, I doubt Chevy is different. I have run 75w110 in my non towing F150 for a few years, but I would not consider it in a tow vehicle.
