Tire Presuure question

[Michael Fowler]

Getting a new truck brings out a flood of questions--thanks for all your help.
The PO put on some very nice alloy wheels and tires. He pumped them up to 80 psi because thats what the sidewall said. Seems like a bit too much to me.
So what pressure should i really run--especially when empty?
What about towing my 6000 pound +/- fifth wheel? I know I need more, but 80 is still more than I need, or am I missing something?

 

[FordGuy100]

That should be fine if they are E rated (I think thats the rating for 80psi). And are you measuring this cold or hot? It shoudl be all good to tow with, and is probably your best bet for fuel economy. The tires I think will wear out a little longer as well.

 

[dakotajeep]

Pros of 80 PSI:
Better MPG
stiffens sidewall (good while carrying a load)

Cons:
Uneven tire wear, unless loaded
Harsh(er) ride

Personally, unless I am towing I usually stay about 5 less than max. A 4x4 mag did a test on tire pressure vs mpg. The higher the pressure the better the MPG. The last few pounds dont make a hill of beans difference. you could probably go to 70-75 to be better off while unloaded.

my .02

thad

 

[FordGuy100]

Personally, unless I am towing I usually stay about 5 less than max. A 4x4 mag did a test on tire pressure vs mpg. The higher the pressure the better the MPG. The last few pounds dont make a hill of beans difference. you could probably go to 70-75 to be better off while unloaded.

my .02

thad

Thats good to know right there, thanks Thad

 

[argve]

I run 55 in the front and 50 in the rear unloaded and 65 in the front with 75 in the rear while towing. My tread wear is even (flat across) with these pressures. You can take a spray bottle on flat dry pavement or concrete and play with the pressures to determine what is the optimal pressures but it's time consuming what I did was just play with them until I seen a flat wear pattern. Took a little longer but worked.

 

[lotzagoodstuff]

I run 55 in the front and 50 in the rear unloaded and 65 in the front with 75 in the rear while towing.

These pressures are what I run and the difference in ride/comfort with the lower pressure is pretty unreal, it feels like a different truck. With 75 PSI in the tires and the air bags filled up out back, the neiborhood speed bumps feel like you are driving a monster truck over a couple of old car hulks.

 

[BigRigTech]

60 front, 70 rear is what I run. Good tire wear so far.

 

[Dsl_Dog_Treat]

Running 70 all the way around loaded or empty and all is good.

Just them dang Rancho RS 9000 XL shocks are what beats be up.

 

[subway]

I run 55 in the front and 50 in the rear unloaded and 65 in the front with 75 in the rear while towing. My tread wear is even (flat across) with these pressures. You can take a spray bottle on flat dry pavement or concrete and play with the pressures to determine what is the optimal pressures but it's time consuming what I did was just play with them until I seen a flat wear pattern. Took a little longer but worked.

funny thats right around what i run to. up around 70-80 i was wearing the middle right out.

 

[LCAM-01XA]

80 front, 60 rear but they're 4 across.

 

[RLDSL]

The door sticker says 58 psi for the fronts on mine. But that was beating me to death running empty and the tire was wearing poorly. I just ran my fronts down to 50 and that feels much better, and handles much better, I'm running 235/85-16 all around

 

[LCAM-01XA]

Forgot what my sticker says, but I remember that when I had the tires as low as they're supposed to be truck was all over the road, feeling mushy and what not - upped the pressure to 5psi under the tire safety limit, and now it handles much much better, still rides like a dump truck but I can live with that.

 

[Agnem]

Michael, I'd chalk the tires and run around on a flat quality surface (you have more of those in Maryland than we do in PA ). Let out 5 pounds at a time, until the tire wears evenly across. That's your empty inflation presure. When you go back to towing, jack em' back up.