Right guys im consfused...

Having never had rims or low profiles before im not quite sure of the correct inflation pressure. On the side of the tyre it has two pressure levels. One says do not inflate the tyre more that 40psi when Setting Beads (whatever that means). And another message says do not inflate more than 51psi... Im very confused... :?

Anyone care to help?

When I was at the petrol station, it said 36 for family cars.... Then again I proberly dont know what im talking about.

my dunlops run 35psi 'cold'

donno if dat helps :?

GBM

if im just doing around town driving normally 35~40 psi or if im going on a bit of high speed driving 45psi

anywhere around 36~44 should be fine

[quote:68d8ec07f0]bit of high speed driving 45psi [/quote:68d8ec07f0]

mmm.. wouldnt you want to have less pressure to allow for heated air to expand? mmm

i was never any good at physics and any sorta science stuff :roll:

GBM

yeah that is true if you where going to a track day put about 5psi less so about 35~40psi to allow for heat expand , but if your going along the highway at speed you want stability and you dont want soggy tyres :x

I would put about 36-38psi for normal driving. Usually cars have about 30psi but that is more for ride quality.

Manufacturers quote low inflation figures to give the car a 'pillowed ride'. I never use a Manufacturers reccommendations as they are grossly under what is safe. I hate seeing those electronic inflators reading '32' psi from the last person who used it!

This is my opinion:

I run 50/ 55 psi in my 18" 225/35 tyres. (Unintentional) Pressures above 90 psi have been seen without tyre explosion, so I'm definitely not worried about bursting.

Low pressures (below 36psi) have the effect that if your car spins out of control, a low inflated tyre would roll off the rim easier and allow the rim to dig in causing the car to flip.

I use higher pressure in my daily driver not because of this (It's too slow), but because it lowers the cars rolling friction resulting in better fuel economy.

I think tyre pressure levels would be something that you'd have to play with out on a circuit to get your best pressure. Lower pressure at the drags gives cars a better take of, but may have the effect of a lower mph due to extra rolling friction.


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:shock: 55psi :!:

How long have you run it with that?? is the ride rough?

I think im going to pump mine up to 51 psi like it says on the tyres tommorow morn... See how we go with that.

I run 50psi in my standard 205/65R15's Pirelli P4000's (complete with plastic covers).

WHY?

1. Better handling. Higher pressure gives less distortion of the sidewall. Just like going to a lower profile!

2. Better wear. I find that at 32-34psi (recommended) i wear the shoulder of the tyre (the outside edges) quicker than the centre of the tyre. Higher pressure in the tyre pushes the centre out, giving better wear. My Pirelli P4000's have even wear across the tyre.

3. High speed runs. I won't talk to much about this, but it is much more stable when "overtaking" 8)

4. Economy. Less rolling resistance as stated. I can do Bathurst to Melbourne (Shell Underhill, the last Optimax station coming out of Melbourne to the north) on ONE TANK OF OPTIMAX!!! :D

BTW they are 35,000 kms old & only half worn. Got them for $115 each. Bargain.

i honestly dont know what pressures are in my tyres - might have to run to the shop tonight to check??

oops!!!

oh well - i dont think i would be running 50psi in standard height tyres - ie 65 profile tyres!! seems a bit high - but i will be running about that in my 235 40's 18'

Manual

rides like a bitch i tell you, the roads around here are as bumpy as hell.

the wear rate has gone right down though. Alot of guys run high pressures around here, mainly coz you can pick up alot of punctures on dirt roads otherwise.

ooh gravel road punctures tell me about it!! my worst - four tyres in a weekend in my old corolla!!!

hmm, bonfire sounded like a good idea to begine with until we used the corolla to collect firewood!!

4 bloody tyres - at least in the corolla it was cheap at only $50 a tyre!!

Manual