Ok, today I checked the air pressure in the new Nokian WR tires that were recently installed on my '03 LS430. It was 30PSI which ain't right. Looking in the glove box, it says to use 32 PSI (all four tires) if you have the P225/55R17 95H tires and to use 35 PSI (all four tires) if you have the 225/55R17 97W tires.

Well, my Nokians are NEITHER. They are 225/55R17 101V tires. I assume they are, however, still a correct tire for the car. The question is what pressure to use. I guess I could put 33.5PSI in and split the difference...1.5 PSI too much or too little should not make much difference. Nevertheless, if there IS a correct answer to my question, I'd like to know it. I don't totally understand the whole tire numbering thing, but my guess is that the tire that I have is a whole lot closer to the second tire listed (the one requiring 35PSI) than to the first tire that I listed. Can anyone who understands this help me make a good decision about this?

 

Assuming the max allowable pressure for your new tires is 35 psi (check that number on the side wall), you should start from 34 psi and if the ride is too rough, then drop 1 psi each time (but not below 32 psi) until you get the best combination of handling & ride.
It's supposed to be 30 psi for my 91 LS but I always have it at 32 psi, which to me is the best compromise. Generally speaking, car manufacturers tend to specify a lower pressure to improve the ride.

tvd51

 

Thanks, but I don't believe it says "maximum allowable pressure". It says THEE recommended pressure.

So, again, what is THEE recommended pressure for MY tires?