I just put on a set of Goodyear Wrangler Radial AT/S LT275/65/R18.
(same tires/wheels that come stock on FX4) The tires read max pressure 50 lbs,isnt that kinda high.You FX4 people,do you run 50 lbs. air pressure?

Thanks in advance.

 

Max pressure is just that.....the maximum you'd ever want in the tire. If you filled it up to 50 psi when it was cold and then headed out on the road, the tire would heat up and could possibly blow.....though I doubt it would.

We have a 2005 FX4 SuperCrew. The factory specs inside the gas lid say 35 psi front/rear. That's what I would run.

 

Here is the key, and believe me it will work. Rotating and ballancing every 3-5,000 miles is the key to keeping those times for a long time. If the tire is wider than the wheel you need to adjust your tire pressure from 45 ish to 38 ish every time you rotate. That way the tire does not only wear in the center, but it will wear more evenly. I have always ran wider tires on stock wheels, and have done this from day one and always get 50,000 plus out of a set of tires. Hope this helps.

 

Definitely not the max for the tire, if you are running an OEM size, what's in your door jamb is a good idea.

This is how a Ford engineer explained it to me. The VOLUME of air in a tire is what supports your vehicle, not the pressure, the pressure is a factor of the volume. The factory decides their numbers based on a balance of safety, ride comfort, tire wear and fuel economy, and you can stray from those a bit, to suit your needs. To over-simplify, if you put a tire on that had twice the capacity of the OEM tire, you would use half the pressure.

 

Tire pressure for that should be 40. 35 would be for a P series tire. The LT275/65R18 came with my truck. Stcker says 40, and that would be what I would run any LR C tires on that truck. LR D or E would be higher. P series lower.

 

X2 mine also display 40. SCab FX4

 

The maximum psi listed on the tire's sidewall is for towing/hauling heavy loads, not daily driving. I've found 40psi is a good starting point.

 

what do you mean by that last sentence that i put in italics? i have aftermarket tires, their max psi is 65# thats not double stock, but still. I run them at the toyo recommended 50# to wear evenly based on the stock rim. if i ran my tires at what you suggest, half the pressure, they'd cup- plus, if i run under 45lbs, i cant get over 7mpg on the highway due to the drag.