32psi all year round for me.

 

Wider tires give a larger contact patch for a given weight. A larger contact patch distributes the weight in a larger area so it takes less pressure to hold up the same amount of weight. However, the best thing to do is play around with it till you find what works with your set up. You shouldn't have to go below the set point on the TPS, 28 psi is a bit low.

 

Yes, 28 is low. No need to go any lower than 32 or so unless you have a specific application like the strip for traction or something. I'd say pretty much everyone should be between 32 and 36, maybe a few peeps a tad higher for some reason or another but nothing above 40.

 

34 always and forever

 

The tire guy was right. Most passenger car tires have a maximum pressure rating in the 45 PSI range. That does not mean you should drive on a tire at those pressures! Unless of course you're longing for the ride of that buckboard Great Grandpa used to drive around the farm.

DOT mandates that every car sold in the US have a label attached to the driver's door designating a recommended operating pressure for it's tires. That's the place to start. Every car I've ever seen has called for cold inflation pressure of low to mid 30's.

LOL, I bought a GTO back in 2005. The first one I drove was horrible, rode like a brick! I almost said no thanks to the car. But, I went to a second dealer and drove another example. Vast difference. Much more supple suspension. After I bought the car, I found out on a forum that GM shipped the GTO from Australia with shims in the springs and the tires inflated to 45 PSI in order to help hold it in place when lashed down to a ship's deck. And, Pontiac dealers being what they are, they often failed to prep the cars properly. Lot's of GTO owners had cars delivered with ridiculously over-inflated tires.

Believe me, you won't like 45 PSI. Beyond kidney health, another reason to avoid high pressures is that your tires will wear unevenly. At high pressures, a slight crown will form causing accelerated wear in the center while the edges lose contact with the road and wear relatively little.

 

I have an 08 X Sport. 33 lbs at all 4 corners.

As for those with 19's, try whatever the G37 coupes are using and depending on the wear of the tires, go from there. If you're on 20's you're pretty much on your own to figure out the optimal pressure.. Most tire pressures are say 32-35 lbs.....

 

In my experiece, stock pressure seems to give a really good balance btw ride and handling - even w/ aftermarket 19" and 20" rims/tires.

However, I always run higher pressure (35 psi or so) with larger diameter rims just to have better rim protection. If I get 20s, I may bump it up some more.

 

50 psi in all 4,

thats not a typo, five zero in all four tires.
very responsive steering and zero side wall role.

and the *** end slides around nicely when i want it to in my 6mt

 

Rough ride with 50 psi. But I understand the fun factory behind your decision. Don't you have rattles ith 50 psi?

tg

 

What kind of tires are you using? Bicycle tires ;-)

I run 35-36 all around. I find manufacturer recommendations generally too low, as they are biased toward comfort vs. performance and optimal tire wear. I think the Ford/Firestone (it was those two right?) tread separation issue was because Ford recommended a lower tire pressure than Firestone had. Pressure too low, tire temp too high, tread separation.

But 50psi. Heck my mountain bike is lower than that.

 

Tires inflated to 50 lbs are a potential blow out risk, not to mention teeth loosening. I believe the reason the max is 45 psi is because above that with the tires heating up, they are tested to fail. A blowout at 70 to 80 mph could end your life. 45 is a cold tire max psi! - not to mention less of your tires tread is in contact with the ground. They become bulged in the center of the tread.

More responsive steering makes sense. It's like running 185's up front. Smaller tires equal less friction/stiction/traction.

 

 

 

I have 19" Falken's on my G and if you go to their site you'll find a series of charts that recommend a different pressures for each of their tires. It makes sense that this value should change as a function of tire diameter and width because although the weight of the car is contstant, the amount of area that has contact with the ground is changing. Plus, some tires are designed to have more pressure in order to keep the sidewalls stiffer (particularly for lowered cars and stuff like that). So potentially, you may want more or less pressure in your aftermarket tires then the OEM tires. I keep mine right at about 40 psi.

Here is that link:
http://www.falkentire.com/#/Tires/LuxuryVip/

 

Not sure if you are talking about that chart I've seen but it only shows the max load. That is actually on the tire as per regulation.

To me it is a debate what was first egg or the chicken. You can't tell just by knowing the tire what pressure you need since you have no idea what type of car they will be on. That is the reason they provide max pressures on the tires not the recommended pressure. Same with the car it tells you the pressure but that is for the oem tires. However I think it is closer to the requried pressure. Since the type of car and the weight has more to do than anything else.

Just my .02

tg