Gentlemen, while communicating with Marshal in his "New Here" AKA "The Build" he informed me that he is running his new General Grabber Red 35x12.50R18 E Tires at 28psi. I know that in reading the https://www.f150online.com/forums/wh...=tire+pressure thread, along with several others, it seems that many of you out there have an opinion that a higher pressure is needed with a larger than factory sized tire.

I am purely looking for insight, and perhaps some personal expressions or experience in tread wear issues with different pressures.

For those of you who have been running higher pressures, how has it affected your TPMS? Anything you did or could do to correct any problems? Are the TPMS problems different in the sub 08 models and the 09+?

I have pretty much decided on Nitto Trail Grappler 295/70/18LT (34.57x11.73) on my Factory FX4 wheels, and am curious about what the consensus might say about pressure.

For kicks, and because I feel like stirring the pot a little today, please allow me to quote Marshall from his thread when I asked him about his choice in a lower PSI.... "the whole concept is to keep the tread completely flat with no positive or negative cupping. since this truck only weighs in at 5000lbs, an E-ply tire is COMPLETELY unnecessary. the number of additional plys, steel belting and sidewall thickness along with extremely hard rubber = the need for low pressure. if anyone tells you otherwise - they're an idiot and i challenge them to do a chalk test."

I should probably do a little research to see what an E ply tire actually is, but isn't that what I have you all for?

Let the games begin.

 

e = 10 ply if im not mistaken

 

Well Marshall will pay one day on the highway at speed when he blows a tire. Hopefully, he won't take any one else out when he wrecks.

http://www.discounttire.com/dtcs/infoAirPressure.dos

http://www.tirerack.com/tires/tirete...e.jsp?techid=1

I guess Ford is all wrong when they recommend 50 psi for their F150s that come with LR E tires.

PS - It has nothing to do with the size of the tire. It has to do with the load range, max pressure, and weight carrying ability for the tire. I can give you examples of 3 or 4 LR E tires in the same size that would have different recommended pressures for the F150.

 

King, any insight into the pressure monitering system, and running higher pressures? I think it's safe to assume that we all know that the light comes on at low pressure, but how is it designed exactly? Does a higher pressure confuse it at all? Is there any way to recalibrate it to know you are running a high pressure to begin with?

 

My understanding of the newer systems (09 up) is that they respond to a drop in pressure of a certain percentage. In the 07-08 sensors, they were even stamped to show a max pressure of 50 psi. The newer ones have no such markings, so I assume that they can be used on any LR tire. There is a procedure in the owners manual to re-register the sensors. My guess is that by doing this, it would reset it so higher pressures can be used. I have not heard of any one having problems with higher load range tires on their vehicles and many have gone to them.

 

Deleted: Not worth my time

 

Like King said.....I sure hope you don't kill anyone when your LT tires blow out from an overheated sidewall due to a very under inflated condition...you have a lot to learn about tires and their construction and their load rating specs and inflation !!!

 

Deleted: Not worth my time

 

you are correct....
If running higher pressures you'll need to reset the sensers so the percentage drop for low pressure warning is maintained...

 

If you convert to the new stem type sensors for the 07-08 MY from Revolution supply...they also have no MAX press. I have them in my LT tires at 50lbs with no problems at all.

 

Well, sorta correct. Keep in mind the factory recommended pressure like this on a door jam sticker is the max pressure and assumes a fully loaded, maxed out truck, up to and including the whole GVWR. If you're driving around an empty pick-em-up truck, even with an E tire, you don't need 50 psi. 28 may be too low, but there's also too high.

 

Well, I have my 295/70/18 Nitto Trail Graps on order, will have em mounted in a week. So, what is a perfect pressure for unloaded city driving on these new bad boys?

 

On my 35" trail grapps is am running @35psi, Discount tire inflated them up to 40psi but I backed them down a bit.

 

i keep mine at 45psi. that works the best for me. i know a lot of people on here with these tires run them at 45 as well.

 

If you look at the numbers, 40 is too low even for an empty F150 with most LR E tires. Especially at the front. Most LR E tires have a limit of between 3000 and 3600lbs. At 40 they are limited to half or less of that weight. An empty 2011 scab is going to run around 5500lbs empty, no passengers. With the biggest amount of that weight in the front. Those tires would be overloaded with 40 psi.
Personally I have run LR E tires at 50 with no problems with wear, and if carrying a load, I did not have to worry about adding air just to do it.

Also the recommendations by NHTSA is that TPM system would alert if the pressure drops to 46psi for a LR E with a max of 80.

http://www.nhtsa.gov/cars/rules/ruli...ule.html?name=

As for the Trail Grapplers, LR E 35", they have a max of 65 rather than 80. 35 is not as bad as the other suggestion, but is still too low. Discount had them about right, although they would have been better at 45 when loaded.


The 295/70R18 has a very high rating for a LR E (4080 at 80psi). You can run them at 40 and be good for even a loaded truck. ASlthough if towing, you may want to run them slightly higher (45) for sidewall support.

Each and every tire is different. You have to look at the numbers for each one to determine what the should be run at.