Just wondering what the proper air pressure is supposed to be for these tires. They are Baja widetrack tires. On my 99 F150 driver's door placard it says to inflate these tires to 35psi in the front and the back. The maximum pressure is 44 psi on the tire. I plan to put about 4-6 sandbags in the box during the winter. Let me know what you think about this pressure. Should I leave the front at 35 psi and put the back a little higher if hauling something?

 

I just put air in our Expedition today. The label says 30psi in the front & 35psi in the back. We have 265/70/17 on our rims. I know the Expedition is heavier than the F150, But I think you should be fine.



https://www.f150online.com/galleries....cfm?gnum=1142

 

You don't say whether you have P265's or LT265's.

I have LT265's with a 50 PSI max pressure. I just took them up to the 50 PSI level today. I had been running 40 PSI before. It's too soon to tell, but seat of the pants feel tells me the truck rolls a lot easier. I plan to run this on the street for a while and see what it does for the MPG.

When I run offroad though I think 35-40 PSI is better as the lower pressures put more of a tire contact patch on the ground.

Tom

 

Everything I have always read, and all my personal experience (and that of my father and friends) says that putting the tires at their maximum or near that is best for mileage and tire life, especially if you are going to be seeing load.

I run 35 PSI on our passenger vehicles and the recommended on several of them is 30 PSI.

Ford is notorious IMHO for suggesting far too low pressures... (See: Firestone tire fiasco... I mean come on, duh, weren't they advertising 25 psi on something that should be 35 psi!!)

 

You should set the tire pressure according to what the TRUCK information plate says, NOT what the tires say. So if you're running the proper tire for the vehicle, it will correlate well. If you are running 8 ply tires on your half ton, well you’re all out of whack anyway..

Remember, if you fill your tires to the MAX. psi, you are actually overfilling them because when you get them heated up that pressure goes up and then you are past the max.

Also, putting them that high, you will wear out the center of the tire prematurely and you have less of an actual contact patch on the road. Ideally you should have the pressure set to the point where the tires contact patch is evenly loaded across the tire for safety and longevity.

Sure you will get better gas mileage and stiffer handling with them too high, but it’s just not a good way to go.

 

The maximum you should inflate your tires cold is what ever is written on the tire, NOT the truck information plate. With a passenger "P" type tire that is usually 35psi max cold, or ambient. This allows for expansion as the tire warms up. (Note: the spec. does not say 35psi max HOT)

My stock P tires that came with the truck had a MAX 35 psi cold instruction. When the truck was loaded to near capacity it had a very mushy feel and did not handle well, and that was at 35 psi cold. Tire pressure can be adjusted for handling, load, and even tire wear to match tire use with the truck

When the truck needed new tires I purchased "LT" light truck, load C, 6ply, 50psi max A/T tires. MUCH improved handling (and traction) both empty and full. This is the type of tire that fits the need and function I want from my truck, without over doing it. When empty the front are inflated at 46psi, the rear to 40psi, When loaded up and/or towing I may inflate them to 50psi front and rear.

The truck information plate does not know what tires you put on your truck or what load you are running. The tire type should match your needs and be inflated according to the tire manufacturers recommendations.

 

BIKENUT......The ONLY time you should use the pressures indicated on your door panel are with the tires that came on the vehicle from the factory. There are a multitude of different tires designed for different driving conditions, and as such the TIRE COMPANY knows better what the capabilities/limits of the tires are and should be. Also depending on the type of driving you are doing you should adjust air pressure. As an example 40lbs hwy, 36-38lbs cty, 30-35lbs gravel road, and 20-25 lbs offroad seems to work perfectly for me. I'm not saying this is right for everyone, but to suggest that the door sticker knows better than the actual tire company or knowledgeable driver is just plain silly.

 

sagittarius1 and MANDRAKE27 are correct. (Sorry bikenut). The door placard is only for the stock tires that come on the truck. If you are running an LT tire that the sidewall recommends 50psi on the sidewall and you only run 35 like the door placard says, then you are going to prematurely wear the outside edges of the tire and your ride will be mushy, handling will suck.

tire manufacturers recommend inflation pressures according to how they designed their tire. Ford has no idea what kind of tire you are going to put on later, but they have to put tire inflation info on the door placard, so they put what is recommended for the tire that came stock on the truck. (usually the sorry crappy POS wrangler rt/s which most ppl take off and replace with a real truck tire soon after the purchase of the truck)

**Ford recommends 87 octane, right? If you change the engine characteristics by adding a SuperChip, you have to run at least 91 octane as SuperChips recommends. If you don't, the truck will not perform properly. Same as changing the tire characteristics by changing to a tire that recommends higher inflation pressures. the truck will not perform properly if you go by Ford recommended tire pressures.

 

aww damnit, you guys are right, I was backwards

Now that I read the posts and think about it, I knew the right way, but these damn brain clouds sometimes.... :o