Hi everyone, I did a search for this problem and I wasn't able to find any information...

I recently read on these forums that switching to 245/40/r18 front and 275/40/r18 rear, would be benificial. I have stock wheels on my 2005 ZR and was hesitant at first but felt reassured that making this move would be good since several people endorsed it and ran it on their wheels.

So Friday, I had 4 new PS2s mounted and balanced, had my alingment done, and drove off feeling happy about my new shoes.

I didn't drive it over the weekend, this morning when i jumped in to go to work, I heard the alram for the tire pressure. I looked and all 4 tires were at 28/27 PSI. I immediately went to the nearest station to fill up and was at 33/35 on the way to work (I have to purchase a new air guage as my old one was lost).

My question is, did I make a mistake with my tire size? Could this be a mounting issue or valve stem issue? They knew I had tire pressure monitoring system and to be careful with the stems.

I am afraid that these tires might not be fitting properly and I may need new wheels?

Any help would be appreciated.

 

Some people have success with these sizes on OE/Stock wheels, some do not (usually TCS/VDC related issues). I had them put 275/40/18's on my rear wheels (stock, 8.5" and no lowering) when I was getting new tires, and they did not look right at all (to me, it looked like too much bulge when the car was put back on the ground). Maybe this could lead to the air leaking issue you are having?

The tech at Discount Tire said he wouldn't recommend driving with these sizes on 8.5" wheels, so I'm stuck with 245/45's until I can get better wheels.

 

Which tire is leaking air?

 

All 4 were leaking air, but all lost about the same amount. i contacted Wheel Works and the tech said it might have had to do with the extreme heat we had that day 104 or so.

I filled up the tires on the way home and noticed that they increased pressure about 4-5PSI during freeway driving. I will monitor it over the next day or two to see if this happens again.

Any idea if it it better to have the PS2s at a higher PSI than normal tires. it says max is 51PSI, I figured maybe 35-40 would be good instead of the 32-34PSI the tire shop set them at.

 

It is when you have the proper size wheels to do it. Putting them on your stock wheels actually hurts your handling. Some people have done it YES , but it doesnt mean they actually hit the corners.

 

That cant be right. Get yourself a good tire pressure gage and forget the TPMS numbers.