Tyre Pressure?

[greenday-rulz21 6]

I can't find the owners manual, and the sticker on the inside of the door doesn't have this size tyre.

What would the correct tyre pressure be for 215/45 ZR17's?

I believe they're on stock motorsport rims, 7.5 all around.

Any help is much appreciated.

[Guest FrantiC]

Doesn't it usually have max pressure imprinted on the tyre wall?

My guess is around 40-45PSI.

Edited February 6, 2009 by FrantiC

[greenday-rulz21 6]

Doesn't it usually have max pressure imprinted on the tyre wall?

My guess is around 40-45PSI.

Oh, is that what you're meant to put in it? IIRC its 50psi (which is bloody high).

I always thought it was around 35psi?

[SIR E30 68]

I would be running somewhere between 35-40psi.. Google around though, you will find some useful stuff

[Eagle 1679]

Manual says 29 F & 32 R

[greenday-rulz21 6]

Manual says 29 F & 32 R

Cheers mate. Thats all I wanted to know, just the manual specs.

[Nobimmer 694]

Doesn't it usually have max pressure imprinted on the tyre wall?

My guess is around 40-45PSI.

I always thought that the max psi number on the side of the tyre was just that, the max PSI that it can take and NOT the recomended manufacturers digits?

[Guest FrantiC]

I always thought that the max psi number on the side of the tyre was just that, the max PSI that it can take and NOT the recomended manufacturers digits?

Yeah, Max is usually around 50psi. So meh, Anything under 50psi.

I do mine to 42PSI.

[Creaver 55]

Arnt those pretty high pressures? My 540i is only running 38

[hybrid 1044]

38 all round for summer town driving. 43 for runs, 46 for the track. winter I run higher than 38 pressures as I get a lot of rough pot holes in my area. 38 for open road to help with ride comfort.

suits my weight vs profile / tire width(s).

its totally depends on your car vs you tire vs what your driving.

[Creaver 55]

38 all round for summer town driving. 43 for runs, 46 for the track. winter I run higher than 38 pressures as I get a lot of rough pot holes in my area. 38 for open road to help with ride comfort.

suits my weight vs profile / tire width(s).

its totally depends on your car vs you tire vs what your driving.

How do you figure these pressures out? Trial and error?

[greenday-rulz21 6]

Probably doesnt have that tyre size because it was not an OE option 7.5 rims generally were 225 or 235

A width what you have would be a good indication

The range of suggestions is a bit extreme depending on tyre brand I would go 36 front 38 rear for premium European tyres and 34 all round for second teir tyres like Sport maXX Bridgestone etc

On the front are Toyo Proxes, rear are bridgestone Potenza's. 215/45 all around.

Cheers for that Josh, I might do a bit of trial and error, see what best suits.

[kiwi535 538]

Arnt those pretty high pressures? My 540i is only running 38

i run e 34 m5 pressures as thats the size tire s/wheels i have...i cant quite rememeber what the pressures are but its something like 39f 42 rear...

Edited February 8, 2009 by kiwi535

[Creaver 55]

i run e 34 m5 pressures as thats the size tire s/wheels i have...i cant quite rememeber what the pressures are but its something like 39f 42 rear...

And what sized tyres/wheels is that Paul?

[kiwi535 538]

And what sized tyres/wheels is that Paul?

either 17x8 et20 or 17x8.5 et15 with 235/45/17 tyres all round

[hybrid 1044]

How do you figure these pressures out? Trial and error?

yeap .. that and the fact Ive stuck to the same type of tires for the past 4 years.

fr 35 rr 30 profiles need a lot more than other tyres. The side wall needs it for support.

Around the track I can afford harder tyre pressures to help the side wall. Wouldnt dare do this on the road as its hard as balls and generally uncomfortible.

[kiwi535 538]

yeap .. that and the fact Ive stuck to the same type of tires for the past 4 years.

fr 35 rr 30 profiles need a lot more than other tyres. The side wall needs it for support.

Around the track I can afford harder tyre pressures to help the side wall. Wouldnt dare do this on the road as its hard as balls and generally uncomfortible.

agreed i generally run slightly lower pressures when commuting...its a wee bit more comfotable,but the hills and windy roads here is hard othe front tyre outside edges esp if pressures arent kept up

[aliluya 0]

I usually run 40 on all my cars.

[Apex Effects 3]

most low profile tyres (ie 215/45/17) have a average max pressure recommendation of 50psi but thats the manufacturers suggested limit for when seating the tyre when first fitted to the rim. for any tyre under a 50 profile run at least 36 for comfort an tyre sidewall support. lower the profile higher the pressure in most cases. suv's(X5 etc) run 40 all round no matter what profile size, reason is the weight of the vehicle is higher. ive found while running my e30 325 on 195/65/14(factory size) 36 in the front an 34 in the rear was good. the ride was firm to soft an had to be doing ridiculous speeds around corners(not that i suggest doing this) to get any tyre squeal(sign of tyres grip level is at its max). so after all that jabbering.

Recomended tyre pressure(as suggested by me a qualified tyre fitter )

215 45 17s 36 or 38psi

225 45 17s 36 or 38psi

235 45 17s 36 or 38psi

235 40 18s 38psi

215 35 18s 40psi

235 35 19s 38 or 40psi(anything below a 35 profile run 40)

235 25 20s 40psi

[greenday-rulz21 6]

^^ Great info mate. Appreciate it.

Haven't done anything about the pressures yet, but when I do I'll put about 38 in I think.

[Apex Effects 3]

^^ Great info mate. Appreciate it.

Haven't done anything about the pressures yet, but when I do I'll put about 38 in I think.

cheers always happy to help out. your running 215 45 17s aye?

try 38 front 36 rear? see how that goes

[greenday-rulz21 6]

cheers always happy to help out. your running 215 45 17s aye?

try 38 front 36 rear? see how that goes

yea mate, 215/45. Will chuck those pressures in tomorrow, see what it feels like.

Cheers

[edhardley 0]

yea mate, 215/45. Will chuck those pressures in tomorrow, see what it feels like.

Cheers

Hey Nick, got pretty much same wheels as yours. 38psi on rear, and 34psi on front is whats reccomended (thats for best performace, but also daily driving). Being rear-wheel drive, and taking into account you need sticky front tyres, it's always been noted to have a higher pressure at back, and lower at front. I definately wouldn't be pumping these specific tyers above 40psi unless you want to increase chances of punctures, sidewall damage and loose some steering feel. Good luck finding a good medium between speed and handling.

[Apex Effects 3]

Hey Nick, got pretty much same wheels as yours. 38psi on rear, and 34psi on front is whats reccomended (thats for best performace, but also daily driving). Being rear-wheel drive, and taking into account you need sticky front tyres, it's always been noted to have a higher pressure at back, and lower at front. I definately wouldn't be pumping these specific tyers above 40psi unless you want to increase chances of punctures, sidewall damage and loose some steering feel. Good luck finding a good medium between speed and handling.

34 psi on low profiles? say hello to impact fractures an quickly worn out tyres dude. 36 would be sticky enough al our customer run that no problems high pressure decreases the chance of side wall damage actually as well not sure bout steering feel thing tho. being rear drive you would want more grip in the rear less likely to spin out from loosing traction. as suggested 38 or 36 for best results. an punctures happen anytime anywhere as well nothing going to stop a nail or screw jamming itself into your tyre dude, but lower treaded(worn out) tyres more prone to punctures as there is a greater surface area contacting the road

[JiB 2]

Well, BMW figures say 323i E36 F30-R36, and we run factory recommended F31-R37 in our E46.

But perhaps this is wrong, Is 215/45R17 a factory E36 size? There's only 225/45R17 in the list?

Note, I am not a qualified tyre person. Just wondering why BMW used such different figures to what you're recommending. Perhaps German roads are much different to ours (this is assuming they use universal pressures for all countries).