According to the manual, 30psi is for the 17's.

 

Thanks !!!

 

Oh, thanks for the heads up. My sales guy stated that 35 psi was recommended. (we all know the sales guys are the experts) I've personally never checked the psi. Car's only 2 weeks old.

Do you think 35 psi would be too much?

 

Make sure you check the tire brands and that it can accomodate 245 for 7.5 rims. Some brand saids you need 8 inch rims for 245. I might up the psi a little but for now I just want to use the manufacturer suggested psi and see how it goes.

 

I am no expert on this but I think higher psi = better mpg but lessens the grip while lower psi iincreases the grip but = decreases mpg. Correct me if I am wrong guys.

If you haven't check, maybe you should. Quite a few people said their tires were 40+ psi when they bought their car and it was very rough on the road.

 

No Way... I just checked, and they're all at 40 psi. Not sure if temperature matters, but she's been sitting in the garage for about 2 hrs.

Seems like I should back off to at least 35 psi.

Any thoughts?

 

Hey Mikeee2

Where did you get those wheels from? I was looking to get a set for my X also. I looked on e-bay and found a set but someone sniped me at the last minute and won the auction!!! Damn them.

Jimmie

 

I work in the tire business and yes 35 is recommended level, in any passenger car anything nearing above 40PSI is too much. Most passenger tires have a max. PSI of 44. The only time you would need to have 44 psi in your tires is if your hauling around a ton of stuff in your car, thus on the the side of the tire why they say max psi:44 at a certain lbs. Increasing PSI does help with handling and fuel economy but you also sacrifice your ride comfort, its all personal preference. As for checking your PSI, you want 35 PSI cold, cold is when the car has been sitting for atleast 3 hours or driven less than 1 mile. after that the tires are hot and your psi reading will be 2-6PSI higher than cold. So to sum it all up, 35,36 is perfect, 40 is a bit much but if you must then go ahead, it wont hurt the tires. You dont lose handling charcteristics if you have the PSI between 30-37. I also have 245's on my 18 sport rims (245/40) because i plan on lowering the car and getting new rims anyways, some think that they may bulge but mine dont at all. Any other questions feel free to ask.
-GP-
-GP-

 

No look further, I got it from a member on this forum. Check the marketplace, private listing on this forum and you'll see 18's from time to time.

 

Defintely drop the psi. 40 is way too much. I wonder why Infiniti doesn't check the tire pressure before giving the car to the customer. That's a bad practice.

 

...again another infomational thread.

Thanks!

 

Gdup35sedan,

Since you work in the tire business, quick question for you. I had the installer take the TPMS out of my 17's and then aired it back up. He said if I plan to use it later on or sell it, it has to re-balance again. Is that true that once you take a tire out from the rim and put it back on you have to balance it? Even though it's the same tire and rim?

Oh, I think one of my tires might be leaking a little air. When I took my car back into garage yesterday it was like 30psi, even though all the other three were 32psi. Then I bumped it up to 33psi. Today I checked and it was 32psi. What could be causing the problem? Maybe it's the damn cheapie gauage. Sometimes it saids 30 sometimes 32. Think I need one of those digital ones.

 

Mikeee,
You dont HAVE to rebalance the tire if you take it off the rim. If you mark the tire with chaulk where it meets the valve stem all you have to do is line it back up when you put the tire back on and it'll be the same as when you take it off. It doesnt work well with low pro tires though because it's hard to turn the tire while its on the rim.
But what the installer was saying is correct if you dont line it up how it is before you took it off. When you dont line it up the weight of the tire shifts to a different part of the rim, therefor it throws off the balance. Same thing if you flip flop tires (putting a tire from going right to left, now the weight is on the other side of the rim)

You dont really need a digital tire gauge, just make sure you dont have a $hitty plastic one. If you get a metal hand held gauge that should be sufficient enough. I've had the same metal tire gauge for over 9 months and it still reads accurate. If the tire is still leaking you could have a small nail letting it leak out slowly or a leak in the bead somewhere.

Also, did the installer take the tire off the rim when he took the TPMS out of your 17's? If so, he isn't very skilled at what he's doing. You dont have to take the tire off to get the TPMS out and install a new valve stem. All you gotta do is break the bead and push the tire down, unscrew the TPMS and pop in a new stem (then there's no need for balancing because the tire hasn't moved from it's original spot on the rim.)Where did you take the tires to get it done?
-GP-

 

you may need to torque down the needle plunger thingy in the nipple.

when I first got my G it leaked about a pound every week. got one of those needle screwdrivers and tightened them all down a bit and the psi has stayed steady for the past two months.

also - regarding balancing. if you reinstall a tire and you dont match up the original points on the wheel and the tire then is will need to be rebalanced. hard to explain - but basically a tire is only balanced based on one orientation on the wheel. make sense?

 

how does the tpms communicate with the rest of the car - is it like RFID?