Tire Pressure?

[KenC]

What's the optimal tire pressure for an e30? I'm running 195/65s if it makes any difference.

[Hallen]

Optimal for what and what make of tire?

It is usually best to start out with the factory recommended values that are usually printed in the owners' manual or on the information plaque on the driver's side door jam.

Adjust from there.

[moatilliatta]

i usually rock 35.

[rThor432]

I run 36-37 normally and I inflate them to 38-40 if I'm doing a road-trip. I run the same pressures on all 4 corners.

99.998% of my driving is on the highway, so that's why I run such high pressures.

[z31maniac]

I run 36-37 normally and I inflate them to 38-40 if I'm doing a road-trip. I run the same pressures on all 4 corners.

99.998% of my driving is on the highway, so that's why I run such high pressures.

Yikes, do you wear out the center of the tires first?

I usually run 32 on the E30.

[rThor432]

Not at all actually. My 195/65/14's on the 318is wore perfectly even, even with the H&R Race springs (which I later changed out for the Sports).

My S52 car isnt a daily driver, but I only inflate those tires to 33-35 tops. Those tires wear evenly as well.

[Jordan325iC]

I run my tires at 38-40psi normally. I don't mind the ride harshness, and I understand that higher pressures = better gas mileage. Is there a downside to doing this?

[asubimmer]

I usually run about 36 on street tires

[dude8383]

I usually run about 36 on street tires

werd, i just mounted my summers and inflated them to 36 psi all around. have been pumping them up @ 36psi for the past 3 summers and the wear is very even.

[Erick]

BMW says that the optimal is 32psi all around, or 36 (might be 38 ) psi in the rear in case there are passengers + trunk full.

Just don't ask E-Rich what he runs. :p I thought I was crazy for rocking 45psi.

[Hallen]

It does depend a lot on the type and brand of tire you are running and how hard you are driving the car. Higher pressures are nice in that you can get better gas mileage and it can help to stiffen up the sidewalls, especially for higher profile tires. Low profile tires need pressures that are a tad higher to insure that you don't bend a wheel on a bump.

Hot pressure is the key. But unless you are tracking your car, you shouldn't need to worry about it. Set what feels good (within the specs) and then watch your tire wear. If the center wears out faster than the edges, then your pressures are too high. If the outside edges wear out faster than the centers, you pressure is too low. (camber must be taken into consideration here.)

[rThor432]

^^Pyrometers are nice for that too.

[Hallen]

^^Pyrometers are nice for that too.

Yes, they are. If you don't have one, you have to look for tread wear and what I call rubber liquefying. It's that strange look the rubber gets after it has been fully heated up on the track. You also look for where the heating stops on the outside. In other words, how far over was the tread rolling in the corners. How far on the sidewall is the wear. There is generally a mark on most tires that you don't want to go beyond. If you are on the line or over, you need to bump up pressures even if the tires are already getting too hot.

[Wishno87]

I know im bumping an old thread guys but does tire pressure also depend on aspect ratio? For example should i run higher pressure on my 17 than i do on my 16 or 14 to protect the wheel?

[Wishno87]

Gais?