[Nsxmatt]

Originally Posted by BTK

Thanks for the good explanation Alpha1BC. As I said, I was going off what was taught to me 30 years ago. And yes, he was an "engineers don't know a thing" kinda guy and said that number on the door jamb was so you would have a softer ride, no other reason. I guess my father didn't actually know everything. Go figure.

Take what your elders say with a grain of salt. On the other hand, take the advice of strangers on a forum with a grain of salt also.

Yes, run the cars recommended psi. Will 43lbs make it THAT much rougher of a ride? No. Will it cause accelerated center tread wear? Yes. But not to the extent people on here make it out be. Most likely you'll not notice that much of a difference in ride, and because of the hard sidewall runflats you'll most likely not notice wear enough to make a difference.

[Airfuel]

Originally Posted by TJay74

The PSI varies depending on the model, the SS 1LE cars call for 32psi cold. The tire pressure on the tires is the max tire pressure for when the tire is at its max load.

As said, no more than 3psi more than the door jamb is a good rule of thumb.

Understood.
The op has an SS, not a 1le.
Most everyone commenting has a 1le.

[00 Trans Ram]

If you are running stock tires, on the street, run manufacturers recommendations.

If you are running stock tires, on an autox or road course, visit the autox/RR forum and take advice from people there.

If you are running aftermarket tires, on the street, run what the TIRE manufacturer recommends.

If you are running aftermarket tires, on an autox/road course, visit the autox/RR forum and take their advice.

For instance, I run Potenza RE-71Rs. Mostly on the street, but the occasional road course day. I run 32psi on the street, and 34 on the track. Unusually low for street tires on a track. But, these tires have unusually stiff sidewalls, and lower-than-slicks levels of grip, so you don't need higher pressures to keep them from rolling over.

As an alternative, every performance tire has little arrows at the edge of the sidewall, near the tread. You want for the wear of the tire, at max cornering, to be at the tip of the triangle. Air up each tire to something like 38, then go somewhere and pull a 1+G turn (both directions, please). Then check the tires. If the scrubbing isn't to the arrows, decrease by 2psi. Repeat until you get the wear to the triangles/arrows.

[BTK]

Originally Posted by 00 Trans Ram

If you are running stock tires, on the street, run manufacturers recommendations.

If you are running stock tires, on an autox or road course, visit the autox/RR forum and take advice from people there.

If you are running aftermarket tires, on the street, run what the TIRE manufacturer recommends.

If you are running aftermarket tires, on an autox/road course, visit the autox/RR forum and take their advice.

For instance, I run Potenza RE-71Rs. Mostly on the street, but the occasional road course day. I run 32psi on the street, and 34 on the track. Unusually low for street tires on a track. But, these tires have unusually stiff sidewalls, and lower-than-slicks levels of grip, so you don't need higher pressures to keep them from rolling over.

As an alternative, every performance tire has little arrows at the edge of the sidewall, near the tread. You want for the wear of the tire, at max cornering, to be at the tip of the triangle. Air up each tire to something like 38, then go somewhere and pull a 1+G turn (both directions, please). Then check the tires. If the scrubbing isn't to the arrows, decrease by 2psi. Repeat until you get the wear to the triangles/arrows.

Great advice. Thanks! I remember chalking the tires to check wear back in the day, just been too lazy lately.

[00 Trans Ram]

Originally Posted by BTK

Great advice. Thanks! I remember chalking the tires to check wear back in the day, just been too lazy lately.

Yup! I remember that, too!!

[Emoto]

Just a minor point: Fuel economy improves with more air pressure in the tires not so much because of contact patch size, but because of decreased rolling resistance. With higher PSI, the tire is less flexible, so that flex needn't be overcome when rolling.

Another point is that the lower the tire pressure, the more the tire will flex. The more it flexes, the more heat will go into the tire. The "right" amount of flex will give you more grip due to the tire compound being up to temp (to a point). Not enough flex impedes traction because the tire stays cold(er) and the tread compound doesn't flex against the pavement imperfections as well.

The PSI spec on the door sticker should be a good compromise of all factors. I will typically run a little higher just for a little more economy on vehicles like my Jeep.

An overinflated tire will wear out the center of the tread first. An underinflated tire wears out both edges first.