What tire pressure do you have?
The dealer returned me the car with the new wheels and tires with the tire pressure from the manual. I think that is a little low...

I seem to recall someone saying 32lbs? About the same as my 18ers. Isn't that pounds per square inch? If so the 20 holds more air but the PSI is the same. Ody's our tire expert.

it really all depends on what your tire is rated. my Nitto NT555's have a Pressure of 50 psi.....I run them about 45-48 range. basically, the thinner tire, the higher the max psi. now, i have to say when I worked at a bike shop, we had tires that could hold up to 120psi that were the same size as the normal ones that held 65psi ....it really depends on the tire....but I am going to say, if your running a 35 series tire on a 20" rim, it should be around 45-50.

I'm running around 38psi with my Nitto N555's and it seems good to me. This pressure was recommended by Dubbed Stealth for 20's.

40+ seems a bit high though, the ride will be rougher for sure.

R.

Nitto 555's should be able to get 30K or more, if you take care of them.
True - I got 30K plus out of my first set of 555...on my second set now and at 45K, they are looking good..I'm very hopeful that I'll get at least the same mileage as the first set...Even with an occasional:burn:

38 PSI of Nitrogen, pressure stays more constant over temp variations

Nitto 555 are probably the best tire on the market in regards to cost and life span. I was going to buy the BFG G-force but, they were about $75 more per tire and wont last nearly as long. Nitto 555's should be able to get 30K or more, if you take care of them.

How are the 555's onthe highway? Are they pretty quiet? I'm thinking about going with those when it comes time.

I'd recommend using your vehicle manufacturer tire pressure specs, regardless of upsized wheels and tires. Running 45psi in your tires is not only crazy, its dangerous.

At MOST I'd say 35psi is acceptable.

it really all depends on what your tire is rated. my Nitto NT555's have a Pressure of 50 psi.....I run them about 45-48 range. basically, the thinner tire, the higher the max psi. now, i have to say when I worked at a bike shop, we had tires that could hold up to 120psi that were the same size as the normal ones that held 65psi ....it really depends on the tire....but I am going to say, if your running a 35 series tire on a 20" rim, it should be around 45-50.

I don't know about motocycles, but with motor vehicles you don't follow the MAX Psi ratings that are found on your tire, you ALWAYS follow the Vehicle manfacturers recommendations for tire pressure. The tire pressure specs can be found in your owners manual, gas filler door, drivers door jamb, or even in your glove box.

Your on your own if you run something crazy like 45psi.

I agree.....mid to upper 40s is way to high and you could have a blow out if you hit a bump.......go let some air outta them badboys and get a more comfy ride too :D

38 PSI of Nitrogen, pressure stays more constant over temp variations

Nitro is cool if you can find it. I can't find any in my area.:mad:

I run 35 psi in my 555's, and don't have any problems. 40 psi or higher is really too much in my opinion.
As far as the Nitto's ride, they are not anywhere near as quiet on the hwy as stock, but they ride really and I'm very happy with the perfomance...I drive my car really hard and they haven't disappointed me in 17k miles or so

Thank you so much for all your response!

I have 245/30R20" Pirelli P Zero Nero's. Max rating is 50 psi. I found the manufacturer recommended tire pressure on the low side as I feel the tire roll in sharp corners. Plus the rims are lower to the ground when I turn my wheel, because the tire is pushed in more. That makes the rims more vulnerable for obstacles on the road like potholes...

So all those factors make me consider a higher tire pressure. I will call Irmscher (where I got the rims and tires from) to ask them their recommendation.

Ok, I called Irmscher and Pirelli. They recommend the manufacturers tire pressure up to +4 psi. So 39 psi would be max. Anywhere between 35 and 39 is up to the driver to test for comfort...

Yes, 50 psi is max for the tire, but you need to consider the cars characteristics.

Hope to help some people out!