What PSI do you run in your tires? - United Bimmer Community

**catalyst** · 11-10-2005, 05:10 PM

I run 45.

**defkon99** · 11-10-2005, 05:13 PM

my kumho ecsta all for reccomend 40 psi

i run 40 in front and 38 in back.

**94bmw325i** · 11-10-2005, 05:18 PM

ill be honest here, no idea.

**voca** · 11-10-2005, 05:18 PM

like 41 psi for me, pnero zero m+s, a little more in rear than front.

**catalyst** · 11-10-2005, 05:25 PM

Quote:

Originally Posted by 94bmw325i

ill be honest here, no idea.

Dude.. go check your psi right now then, whens the last time you did? Your probably eating right through your tread..

I completely change the air in my tires every 2 or 3 weeks.

**Dudesky** · 11-10-2005, 05:26 PM

And you guys aren't bouncing around all over the road? I've tried different pressures, but what worked well was what is printed on the door: 32 rear, 29 front. I run 215/45's on 17 x 7.5 rims, with stock suspension. If I go higher than what's recommended by BMW, the suspension gets all weird & bouncy, losing grip over bumps and the antilock goes haywire.

**catalyst** · 11-10-2005, 05:29 PM

Quote:

Originally Posted by Dudesky

And you guys aren't bouncing around all over the road? I've tried different pressures, but what worked well was what is printed on the door: 32 rear, 29 front. I run 215/45's on 17 x 7.5 rims, with stock suspension. If I go higher than what's recommended by BMW, the suspension gets all weird & bouncy, losing grip over bumps and the antilock goes haywire.

lol, it is pretty bouncy like it is, but it handles alot better with 45 psi than it does with around 35.

**Dudesky** · 11-10-2005, 05:31 PM

^^^Heh, maybe for you. Anything over 33-34 on my car, and the wheels feel like fricken basketballs.

**voca** · 11-10-2005, 05:38 PM

that could have to do with the fact that you, dudesky, are running 17in wheels and catalyst is using the stock wheels with a larger section height and lower tread width. but, I myself have 17x8.5in wheels and about 41 rear and 39 front feels right for my car.

**Rooz** · 11-10-2005, 06:06 PM

On my low profiles I run 40-42 on the older tires (the 15" 36)

nick_318is · 11-10-2005, 06:38 PM

My summer wheels(in my sig) I run at between 35 and 40. My winter wheels I will run at the slightly harder then manufactures specs. My road bike i run at 110.

**fredo328** · 11-10-2005, 08:51 PM

Quote:

Originally Posted by catalyst

Dude.. go check your psi right now then, whens the last time you did? Your probably eating right through your tread..

I completely change the air in my tires every 2 or 3 weeks.

You change your air in the tires every 2-3 weeks??!?!!??!!?!WTF!?!??!

**Tochenzo** · 11-10-2005, 10:00 PM

i think i run about 35-40 as well, i guess ill have to go check lol

**catalyst** · 11-10-2005, 10:26 PM

Quote:

Originally Posted by fredo328

You change your air in the tires every 2-3 weeks??!?!!??!!?!WTF!?!??!

haha, yes. I ussually check my pressure every 2 weeks, after around a month, when im checking the pressure again, i just let it all out then put new air in, it only takes like 30 seconds extra for each tire.

I guess i should mention i have a compressor system at my house.. that makes it a little less weird.

Voca: im running 17's.

**voca** · 11-10-2005, 10:39 PM

Quote:

Originally Posted by catalyst

Voca: im running 17's.

oh, I did not know, sorry.

I figured the bottle caps in your "Rate my car" were up-to-date. my bad.

**94bmw325i** · 11-11-2005, 01:09 AM

Quote:

Originally Posted by 94bmw325i

ill be honest here, no idea.

No like I checked it not that long ago, but don't remember what I pumped it up to, maybe 37 PSI or so?

**brien4787** · 11-11-2005, 01:12 AM

32-33psi or so

damn... some of you guys with over 40psi? thats nuts

**BaLAnCe17** · 11-11-2005, 03:53 AM

ya, over 40 seems like a lot...im around 38-32 no less than 32

**Dudesky** · 11-11-2005, 06:07 AM

Here's some info I found which may be of use here:

Quote:

Some people aren't sure where to set their tire pressures. The one thing that is certain is that the maximum inflation pressure on the sidewall is not the right one to use. The vehicle manufacturer's recommendation is always a good starting point. It will be somewhere in the car. This used to be a sticker in the driver's door jamb, but more and more it's located on the back of the gas filler door. If that fails, the information should be in the owner's manual. Sometimes, there will be a range specified, or two different recommendations, depending on load. Anywhere between these numbers should be safe.

Changing the tire size or going to a plus-size fitment will change the required inflation pressure somewhat. Within the range of optional OE tire sizes, the vehicle manufacturer's recommendations should be followed. For sizes outside the range, the tire manufacturer should be able to help. Yokohama, for instance, includes pressure recommendations for stock and plus-sizes, by vehicle, in its annual Fitment Guide, which your tire dealer should have a copy of. Typically, these are 0-3 psi higher for a Plus-one or Plus-two fitment. Also listed are maximum load ratings at maximum inflation pressure for each size of each tire Yokohama makes.

If the recommendations you find leave you with a range and you want to know more specifically, you can experiment. Air, after all, is free. A change of 2-3 psi can completely change a vehicle. An underinflated tire will ride smoothly but feel sluggish, have mushy turn-in and go around corners with high slip angles or just not much grip at all. An overinflated tire will feel harsh on impact and over smaller bumps, and while responding crisply, will lack grip when pushed hard. To an experienced person, these characteristics are obvious even from the passenger seat. Try the minimum and maximum of your target range, and maybe slightly outside it, and decide what you like.

In the event that you aren't able to find a recommendation for your car, or the tires on your car are so different from those that were originally fitted from the manufacturer as to be incomparable, we received the following rule of thumb from Oscar Pereda, an engineer for BFGoodrich. He calls it a "realistic starting point," saying it has never been just right, but is a good place to start. The rule is:

(Vehicle Weight in lb/100) + 2 psi at heavier end + 2 psi all around if suspension and alignment are stock.

Example: Stock 911, 3,000 lb.
(3000/100) = 30 psi
Add 2 psi all around = 32 psi
Add 2 psi to heavy end = 34 psi at rear
With modified suspension, the result is 30 psi front, 32 psi rear.

**bmwcrazy** · 11-11-2005, 07:14 AM

Yeah, i usually go with what the car says