Newbie needs tow vehicle PSI advice

Gdetrailer wrote:

K-9 HANDLER wrote:
Dude Id just run 60 in all the time.

There is no "one size fits all" in the situation.

Over pressuring the tire without enough load will result in poor traction, poor handling, poor braking, excessively hard ride and poor tire wear taking the centers out of the tire.

I have a 2020 F250 with load range E, factory door sticker min is 55 PSI but tire can take 80 PSI.

However, the empty weight of my F250 is nearly 1,000 lbs HEAVIER than a F150.

I typically run 70 in front and 68 in rear when empty. When towing air up to 80 PSI on rear and 78 PSI on front.

That 2 lbs differential is because of the weight differences between front and rear when empty and loaded, running same pressure can affect ride and handling. This comes from experience, having owned a 97 Heavy half (light duty F250), 2003 F250, 2006 F250, 2013 F250, 2019 F250, 2020 F250..

But keep in mind what I do for my F250 may not work at all for the OPs vehicle.

There has been more than once where some folks have done a "chalk" test on the tires, that is where they spread chalk on the tire then roll the vehicle and check to see how well the chalk transferred to the pavement. Too much air and only chalk in the center transfers, too little air and only the sides transfer. Either way will cause excessive wear on the tire.

Something else OP did not consider, Load range E tires are heavier, about 3lbs per tire.. Does not sound like much but that extra weight does impact fuel economy, braking and handling if vehicle was not specifically designed for that.

He asked I said Id run 60.

I've kept things stupid simple over many years of towing.

Trailer tires inflated to max PSI.
Tow vehicle is increased 10 lbs over door sticker recommendation which is a daily driver recommendation.....worked for over 20 years.

K-9 HANDLER wrote:
Dude Id just run 60 in all the time.

There is no "one size fits all" in the situation.

Over pressuring the tire without enough load will result in poor traction, poor handling, poor braking, excessively hard ride and poor tire wear taking the centers out of the tire.

I have a 2020 F250 with load range E, factory door sticker min is 55 PSI but tire can take 80 PSI.

However, the empty weight of my F250 is nearly 1,000 lbs HEAVIER than a F150.

I typically run 70 in front and 68 in rear when empty. When towing air up to 80 PSI on rear and 78 PSI on front.

That 2 lbs differential is because of the weight differences between front and rear when empty and loaded, running same pressure can affect ride and handling. This comes from experience, having owned a 97 Heavy half (light duty F250), 2003 F250, 2006 F250, 2013 F250, 2019 F250, 2020 F250..

But keep in mind what I do for my F250 may not work at all for the OPs vehicle.

There has been more than once where some folks have done a "chalk" test on the tires, that is where they spread chalk on the tire then roll the vehicle and check to see how well the chalk transferred to the pavement. Too much air and only chalk in the center transfers, too little air and only the sides transfer. Either way will cause excessive wear on the tire.

Something else OP did not consider, Load range E tires are heavier, about 3lbs per tire.. Does not sound like much but that extra weight does impact fuel economy, braking and handling if vehicle was not specifically designed for that.

A LT tire will need around 50 psi for the same load carrying capacity as a P tire at 35 psi when you look at tire mfg load/psi minimum pressure charts.
A P tires max load capacity comes at 35 psi. Increasing to 44 or 51 psi just stiffens the sidewalls.
Tireman9 and CapriRacer mention this in the tire safety blogs. Both are tire engineers and both have tire safety blogs that need to be read by all who pull a trailer.

Most newer std duty 1/2 ton trucks wheel can take 60-65 psi but I sure wouldn't over pressure any wheel. Having hauled for a living I know from real world experience what happens to a steel or aluminum wheel carrying a load and its over pressured above its psi rating. It was a expensive lesson in not following ratings.

Thanks everyone for your suggestions. Yes I went way overkill with E rated tires, but it is what it is. As several have said 35 PSI is on the door sticker but that was for the original passenger tires. I was concerned about the rim PSI tolerance as well, but even at 50 PSI I would be over the weight limits of the truck (so I'd never need to go to 80), and I can't imagine any aluminum rim out there wouldn't handle 50 PSI. In any case, as I said in my original post, I'll probably start at 45-50 and see how it goes. At that PSI I'm still well under the max load of the tires. My biggest concern there would be uneven wearing of the tires. If anyone else has comments please feel free to contribute. Thanks again.

jdc1 wrote:
Look on the sticker on your door jamb.

Maybe yes, maybe no !

If it came from the factory with "P" rated (passenger) tires, that number is too low for "LT" rated (truck) tires.

SWAG : Look at the max pressure rating on the side wall and drop down 5 - 10 PSI.

Dude Id just run 60 in all the time.

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..

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

I ran LT tires when I had an F-150. Recommended pressure was around 40psi. When I towed or carried a heavy load, I bumped up to 50psi front and rear. That was plenty.

My current tow vehicle came with LT-E rated tires and door sticker says 50psi front, 60psi rear to support 4500 pounds on front axle, 5500 pounds rear axle, and 8600 GVWR. I bump each up by 10psi when I tow.