Best Tire PSI for 35x12.5r20 tire

Payton34 · May 15, 2015

What would be ideal PSI for Mickey Thompson ATZ 35x12.5 tires Im at 37psi now.

chebby guy · May 15, 2015

web site say's 62psi

Payton34 · May 15, 2015

62 is the max psi. The stock tires show the max psi is more than the 32-35 GM recommends. All tires show a large range. Right now when I turn I feel the nobs of the tire from the sidewall edge.

tootall87 · May 15, 2015

One way to figure out proper tire pressure for larger tires is as follows. Recommend around low 30s to start with. Chalk the tire across the tread about 10 inchs along the circumference. Drive over the mark. If the chalk mark on the pavement is not showing the outer edges, let some more air out. If the chalk shows darker on the edges than the center, put more air in and re test. How we figured out proper tire pressure in our Jeep on 35s.

Please God do not put 62 psi in your tire...

Edited May 15, 2015 by tootall87

CAtaylor · May 16, 2015

Or...take you original tire load rating and devide by the recommended pressure. Take that number and devide it into the new tire load rating to get the pressure. It won't be exact but it will get you very close. Not all tires have a flat tread pattern so the chalk test doesn't always work. Granted most of the time it will get you very close also.

Spurshot · May 16, 2015

What would be ideal PSI for Mickey Thompson ATZ 35x12.5 tires Im at 37psi now.

Depends....

On the highway to get the best fuel economy...max pressure

To get the best steering response and handling...probably near max pressure, but experimenting would be needed.

For a daily commuter...I'd pick something between tire contact/even wear, and fuel economy

For off-road in the sand, air em down.

Payton34 · May 16, 2015

Or...take you original tire load rating and devide by the recommended pressure. Take that number and devide it into the new tire load rating to get the pressure. It won't be exact but it will get you very close. Not all tires have a flat tread pattern so the chalk test doesn't always work. Granted most of the time it will get you very close also.

I will try this. Currently when Im turning I feel it riding on the side edge lugs and can see the wear. If I do the calculation against the 65psi max rating I should be 48-50 in front and 54 in rear

CAtaylor · May 16, 2015

I will try this. Currently when Im turning I feel it riding on the side edge lugs and can see the wear. If I do the calculation against the 65psi max rating I should be 48-50 in front and 54 in rear

That will be pretty close. Some tire manufacturers have inflation tables avaliable also.

Spurshot · May 16, 2015

There's also the large difference in diameter and width to consider. This causes a much larger contact area to support the weight. A tire with twice the contact area, aired to the same pressure as the smaller tire, will require approximately twice the downward force to compress the tire the same amount. So a larger tire needs less air to do the same work. Or, a larger tire at the same pressure may seem stiffer in some situations.

Edited May 16, 2015 by spurshot

Rewillia · May 17, 2015

Running the Toyo 295/55/R20 10-ply Open Country ii eXtreme AT's my tire dealer recommended inflation to the truck's recommended PSIG of 35-38lbs. Conversely, when I had my winter tires rotated off by my servicing GM dealer they inflated the Toyo's to 60 psig which I found to be too hard/stiff and have since gone back to 38 lbs for a much smoother ride. Right or wrong I don't know but the 38 psig is what I am sticking with and should I end up with premature wear will roll the Toyo's off and move to a different tire/tread pattern. I like the Toyo's so I hope that won't be the case.

sealteem1 · May 17, 2015

I run 40psi in my Mickey's never had any issues.

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Payton34 · May 17, 2015

I did the percentage calculation ond put 47 in front and 51 in rear and its taken care of the front sides wearing in turns.

stock tire max psi is 44 psi

GM recommends 32 front stock(32/44=.72x65=47)

and GM recommends 35 rear stock (35/44=.795x65=51)

Think I did calculations right

Rewillia · May 20, 2015

Running the Toyo 295/55/R20 10-ply Open Country ii eXtreme AT's my tire dealer recommended inflation to the truck's recommended PSIG of 35-38lbs. Conversely, when I had my winter tires rotated off by my servicing GM dealer they inflated the Toyo's to 60 psig which I found to be too hard/stiff and have since gone back to 38 lbs for a much smoother ride. Right or wrong I don't know but the 38 psig is what I am sticking with and should I end up with premature wear will roll the Toyo's off and move to a different tire/tread pattern. I like the Toyo's so I hope that won't be the case.

I contacted Toyo to question them on proper tire inflation of their 295/55/R20 E/10-ply Open Country ATii eXtreme tires I am running and to get their advice. They responded stating they recommend I run 45 psig on my particular truck owing to the 2,300 lbs per tire vehicle load requirements of the 2014 K1500. So I'm going to up the pressure from the current load of 36 lbs to 45.

For those who might be interested; here is the reply I received from Toyo;

Thank you for contacting Toyo Tires USA. Your vehicle came with a P metric tire which is considered a passenger 4 ply rated tire which offers a more comfortable ride, and less weight for better rolling resistance, offering better gas mileage. Since you have gone from a P- passenger build tire to an LT-light truck, the difference you may notice will be a stiffer ride, which is due to the E/10 ply rating for vehicles that require heavier load, vehicles that tow also will use heavier duty tires. You may also notice due to the weight of the tires a rolling resistance change that may slightly affect your gas mileage.

Tire pressures are based off of the vehicles actual load requirement. We determine pressure by using the stock tire and pressure recommendation to find the load and use that load to find the new pressure for the new tire size.

Based off of your vehicles load requirement of 2,300 lbs. per tire, your new Open Country ATII LT295/55R20 would need to be ran at cold pressures of 45 PSI. This will meet the same load required and offer the best wear for your tires. Running under 45 PSI is not recommended as the tire is now running under pressure and over time will not only wear faster, but can compromise the internal structure of the tire and lead to a tire separation. Running the tires at 60-62 PSI would be over-inflated, causing the center of the tires to wear faster and not providing the best "footprint" grip of the tire.

If you need anything further please let us know.

Sincerely,

Consumer Relations

Toyo Tire U.S.A. Corp.

5665 Plaza Drive Suite 300

Cypress, CA 90630

800-442-8696

Edited May 20, 2015 by rewillia