I have a 2006 Screw with the 20" pirelli's and I'm wondering what tire pressures others with same tires are running and why . Ford and the Pirelli say I should be running the pressures on the door 35 lbs {neither could or would give me an explanationas as to why}. The dealer is telling me i should run 45 lbs which seems excessive to me . As u can probablly tell I have no clue about tires ,,,,,,,,,, HELP !!!!!!!!!!!

Thanks in advance
Larry

 

If the tires are P rated (look in front of the size markings on the sidewall), then I would start at 35 and go from there (adjust based on wear characteristics as well as ride comfort).
For LT rated tires, start at 40-45.

 

I run mine at 35 lbs and have a very nice ride, when I tow my trailer I pump them up to 44 lbs which is the maximum pressure listed on the sidewall of the tire, to adjust for the heavy load.

 

^^^ what he said ^^^

You can eek out every last bit of potential mileage gains by running them @ 44 psi, but the ride does suffer some...

40 psi is what I use (kinda splits the difference) - check 'em often

Man - you noticed these things love to pick up & fling stones?

Cheers
Grog

 

i run just under what the tire says.

 

i dont have the pirellis but have the same size tire. i run 40psi

 

Run what is on the door. That is the pressure the tire was tested at for the size and weight of the truck for the best wear and performance. On that tire, max pressure is 44 psi. It's an extra load p-series tire. It will handle 2403lbs at max, per tire. As your truck doesn't even come close to a 10k GVW, it will handle just about anything you do at 35. That is 80% of max pressure. Assuming at 80% of max pressure it can handle 80% of the weight, that is still 8k, more than your GVW. Now if you have the heavy payload (8,200 gvw), then I would bump it up a pound or two.

 

I know this thread is old, but this is the best advice I have found so far. Thanks a lot!