I have Nitto 420s Size 305 40 22. The maximum air pressure is 50psi. My question is what is the minimum air pressure I can run without damaging the tires. I don't have a load or tow anything and I was just trying to smooth the ride a little but I don't want the tire to wear wrong. I asked Nitto and they don't want to comment, They say "The NT420S size 305/40R22 is not recommended for your vehicle due to the load carrying capacity", and "At this time we cannot recommended an inflation pressure due to the misapplication. . OK, I understand they don't want to be on the hook. Can anyone give me a hint or personal experiance

 

i run 45 in my pro comps and have not had a problem. i hope this helps

 

Great thanks

 

That size tire is rated for 2600 lbs @ 50psi. I would definately keep the front tire pressure @ 50psi for safety reasons. Probably can drop the rear by a few pounds if not towing.

MikeyB

 

45 in the Procomps? I run 40 front and 33 rear right now to make them sit flat on 8.5 rims...no problem at all. Look at the tread...go from there.

I would not go down too low on that tire...

What is the weight rating?

 

I have the Nitto terra grapplers 305's and I'm running 45 in the front and 35 in the rear. I tow trailers pretty often and I have not had any problems. The tires are wearing fine as far as I can tell. I've put about 30,000 on them so far with about 50% tread left. Hope that helps

 

Problem is that the tire carcass is the structural member and in order to function properly must be inflated very close to the recommended pressure. Have talked to our tire engineers about this as well as Goodyear’s and Michelins. If you do not the constant flexing in the tire side wall builds up excessive heat and flexes much more than it was designed to do also causing that part of the carcass to weaken...

Nitto will not give you an answer because when your relatives sue them for your tire blowing out and rolling down a hill with you in it would be very expensive....... LOL

 

Weight rating is 2600lbs, my rims are 10" and they are performance street tires. I don't know if that makes a differance. I have 45psi in all four. I'm just trying to make the ride a little softer but with the price of the tires I don't want to compromise the life of the tread.

Is the max pressure the same as the recommended pressure. The tire wall says 50 psi "max". I have a bumper pull camper thats about 6000lbs, how can I determine the load pressure, I guess a weigh station, LOL

 

You need to run 50 in them at all times. I have the same tires in a 305 50 20. I was told that to get max life and not risk something serious happening you need max air. Even though they are not reccomended for our trucks you can run them by the weight rateing. As heavy as our trucks are you need the max amount of air to be safe. This is what i was told by the guys we buy tires from for our tractors and equipment, i am on my second set now and i love them even though nitto didnt respond to me too.