Newbie needs tow vehicle PSI advice

MitchF150 wrote:
People.. He put aftermarket LT E tires on the truck... The door sticker and the manual will be for the P rated tires and will likely say 35..

I had LT E tires on my old F150 with 16" wheels and I ran them at 40 when empty and bumped up to 50 when towing. Way overkill using those tires.. I had LT C tires before, but could not get the tire I wanted in C, so settled on the E's..

I have 20" "XL" rated tires on the 13 F150 and they are perfect fit for this truck and the load.. I bump 'em to 50 when towing. 40 running empty.

Good luck! Mitch

Correct, OP has a 2010 which has AFTERMARKET LT tires which are in E weight rating and is extremely over excessive in capacity.. TOO much capacity I might add.

From HERE

That tire has a weight capacity of 3415 lbs at 80 PSI or 6830 lbs for the axle at 80 PSI which is excessively above the axle rating.. Which from what I have been able to determine for that year the absolute max GVWR is 8,200 lbs, I suspect the rear axle gross weight would not be much higher than 4,500 lbs..

The tire pressure chart on the door are thrown out with this tire choice and not reliable.

OP SHOULD have gone with Load Range C in this tire which would be a far better match which gives 2553 lbs at 50 PSI or 5106 lbs at 50 PSI.

A GOOD tire shop would have advised to use load range C and against the Load range E. Not to mention the rims may not be rated for 80 PSI!

Since the OP has the tires, and they have a inflation/weight chart, they will need to select the pressure based on the max weight they are expecting to have for a load.. A lot of guessing.

I would suggest going to the higher PSI for the max load expected however, I would not exceed 50 PSI unless you have been able to determine the pressure rating of the rim exceeds 50 PSI (that info typically is on the inside of the rim, one would have to dismount the tire to find it). This may lead to underinflation for the load at 50 PSI.

I would not run 35 PSI, that is FLAT for a LT tire and will most certainly lead to failure due to heat build up even when lightly loaded.. Most likely better to run 45-50 PSI, yes, it will be a stiffer ride but better than a blowout from under inflation..