Correct Tyre Pressures?

[jonny116]

Hi,

Iv got 225/45/17's on and just had a flat but only just thought what is the correct tyre pressure.

Ive been running on 31psi on the back and 28psi on the front, i know that is correct in the manual for standard tyres.

Surely with it being low profile it should be a higher pressure, it does say max pressure is 44psi on the tyre.

Can anyone help?

Thanks

Jonny

[1996 328ti]

Originally Posted by jonny116

Surely with it being low profile it should be a higher pressure, it does say max pressure is 44psi on the tyre.

Not really. Construction of the tire is different and doesn't require a different pressure.
I'm not even sure what I have in my street tires. A good rule of thumb is a few pounds over what the factory recommends, front and rear.
I would not go to the max especially since tire pressures increase with heat.
I don't know. 38 front and rear might be good. Some people like to have less in the front. On the street I never really found a difference if I had staggered pressures or not.

[stormos]

got mine on 25psi for some reason. works so i am not going to mess

[1996 328ti]

Originally Posted by stormos

got mine on 25psi for some reason. works so i am not going to mess

I would check for uneven tire wear. You might have more wear towards the outsides. |__/~~\__| (low pressure)

[DustenT]

A simple way to figure it out is take the weight of your car (2800 in my case) and divide by 100, so 28psi. This should give you a good baseline, then add or subtract depending on road/track and temperatures. I run 30.5psi in all 4 corners.

[3184ever]

I work at Discount Tire and have for some time now... So i consider myself somewhat of an expert on tires. You really only want to increase the tire pressure if its an extreme low profile tire. Even then you would never want to put it more then 35. With the tires you have on there now, keeping a stock air pressure would still be ideal. 28 or 29 in front and 31 or 32 in back. IE. Inside the driver door on the vertical post will have your recommended tire pressures.

[snwbrdrbum10]

well, i work in a tire shop...we normally sit most cars at 32 all the way around...and 35 for trucks/vans...The higher your PSI the better gas milage, however, rougher ride...also, never exceed the max PSI warning.. I stick mine at 34 all the way around...good solid grip and good gas milage...30 avg.

[Panzer_M]

34 ft 36 rr
205/50/16 BF Goodridge G-Sports

[cossieturbo]

My 2 Cents for what it's worth. Because that's all I have in my Piggy Bank. Let's be conservative and say I have been around, worked on and sold high end cars for quite some time... and lets say most of them use Low Profile tires.

SO the rule goes like this. Low Pro tires of wider stance do require more pressure to support the center of the tire. It’s based on the physics of the support points versus distance from contact/pressure points. Your tires are not wide and or low enough to really worry about though.

The maximum tire pressure listed on the Tire is not ideal and NOT recommended. I find that every different Tire seams to want a slightly different pressure. The best thing you can do is stay between Factory listed pressure and 34psi COLD for street use on most common sized tires.

The 318ti has an odd quirk though with most tires. It can wonder a bit on the road if the rear pressure is not higher then the front.

I set mine COLD at 31-32psi Front... &...33-34psi Rear.

In racing we play with our tire pressure by 1psi increments to find what works best. Play around with your pressure and find what you like. Factory tire pressure is a base set for ride and mileage (in most cases).

We all know that most people drive around with crazy pressures at each corner because they do not realize how important the tires are. Just keeping the pressure up to safe levels is 90% of the battle.

cossieturbo

[jonny116]

nice one!! thanks for the comments.