Best psi for 2000 330ci on 225/40/18

on 34 all around.. Seems too high?
What's the recommend from bmw

I run 35 all around..

does making the rear a bit higher psi make the car balance better? make it less understeer?

35 all around! Don't mess with it, different psi in the front or rear is not gonna make you a better driver.

I tried 35 all around, the car accelerate faster. but bouncy.
and I feel 34 seems to have more traction. Anyone run 34 here?
I have Dunlop star. anyone with that?
also do your traction control light goes on on bumpy rounds?

Originally Posted by ajai

I tried 35 all around, the car accelerate faster. but bouncy.
and I feel 34 seems to have more traction. Anyone run 34 here?
I have Dunlop star. anyone with that?
also do your traction control light goes on on bumpy rounds?

Is this for daily driving, track, drag? If so psi is not gonna feel any different by 1 psi. Your butt dyno might feel it, otherwise no big difference.

well in mine I feel a huge different of the accelerate.
the car feel lighter maybe u should say. So pick up faster
But 34 seems to have more traction.

Originally Posted by ajai

well in mine I feel a huge different of the accelerate.
the car feel lighter maybe u should say. So pick up faster
But 34 seems to have more traction.

Ok buddy

So 34.5 psi should be the best of both worlds.

i have 225/40 on all 4 corners. i do Michelin recommendation of 39 on every corner

Exactly.

Sent from my SCH-I535 using Bimmer App

There will be no real world difference between 34 and 35 psi. If you're feeling anything its the placebo effect.

Originally Posted by Gary@Tirerack

There will be no real world difference between 34 and 35 psi. If you're feeling anything its the placebo effect.

I find a weird thing is that, I have front -2.30 camber , 0.1 toe out
however the tire wear is at the outer side where the tread meet the side wall.
I suppose it should wear the inside since it's neg camber. if that is the case which cause my tire so slippery, if I change it to the opposite side and also put them in rear instead, will it solve the problem? since the outer will become inner wear, and the rear doesn't need to turn so it casue less affect I guess?

I run 36 all around on 225/40 and 255/35

Originally Posted by ajai

I tried 35 all around, the car accelerate faster. but bouncy.
and I feel 34 seems to have more traction. Anyone run 34 here?
I have Dunlop star. anyone with that?
also do your traction control light goes on on bumpy rounds?

Traction control light coming on on bumpy roads means your suspension is done.
There's no difference between 34 and 35 on the street.
The door jam (just like on every other car in the world) tells you the recommended pressures for your tires.
Anywhere between 32 and 38 should be fine for the typical e46

Just so this is clear: decreasing your pressure does not increase traction on pavement.
However neither does increasing your pressure.
There's an exact pressure for each tire to be under certain conditions for maximum grip.
It all depends on weight of car, temp of road, suspension, tire, tire temp, road conditions and so on.
To simply say that "increasing or decreasing your pressure adds grip" is ignorant. Especially for street driving because you're not loosing grip. And if you are something on your car is inadequate or you drive like an idiot.
My car will grip to worlds end on the street.

Track driving is another story and 0% of people in this thread do it. I guarantee it

Originally Posted by peytonracer4

Traction control light coming on on bumpy roads means your suspension is done.
There's no difference between 34 and 35 on the street.
The door jam (just like on every other car in the world) tells you the recommended pressures for your tires.
Anywhere between 32 and 38 should be fine for the typical e46

Just so this is clear: decreasing your pressure does not increase traction on pavement.
However neither does increasing your pressure.
There's an exact pressure for each tire to be under certain conditions for maximum grip.
It all depends on weight of car, temp of road, suspension, tire, tire temp, road conditions and so on.
To simply say that "increasing or decreasing your pressure adds grip" is ignorant. Especially for street driving because you're not loosing grip. And if you are something on your car is inadequate or you drive like an idiot.
My car will grip to worlds end on the street.

Track driving is another story and 0% of people in this thread do it. I guarantee it

Thanks for the detail.
My suspension is on new coilover, I guess maybe I set it too stiff.
the reason why I concern so much about the grip is because hong kong have very bad road condition, bumpy and very oily.
especially in rain, the oil on the street are crazy. And from my knowledge they use different materials for the roads then America or Canada.
when I was in Canada I never got this kind of problem.
also I know it'ssound stupid that I said I feel the different from 34 to 35.
But maybe it's due to I have a little overboosted rack, so I seriously can feel a bit different.

If you're on crappy roads your best shot for good traction is good tires. They will make much more difference than pressure. A quality tread pattern will help.
Oil is very slippery no matter what pressure or tire. If you encounter oil just be careful. That's all you can really do.

Originally Posted by peytonracer4

If you're on crappy roads your best shot for good traction is good tires. They will make much more difference than pressure. A quality tread pattern will help.
Oil is very slippery no matter what pressure or tire. If you encounter oil just be careful. That's all you can really do.

The Z1 is quite a good tire.

most people use z1 star here , or re001 .
ps2 or etc is just not suitable here.

I usually do 35psi, but I'm doing 32 at the moment. : ) Less bouncy.