Good Street Tyre Pressure

[KRiMiNaL]

What tyre pressure should i be running on the street. I wana stop the wheel spin i get in first gear.

[Sydneykid]

I vote for 30 psi cold.

[Sarkis]

I use 36 PSI.

[leech_]

i use 36psi as well but that is after i have driven around so cold i guess what would that make it around 32i guess.

[KRiMiNaL]

And wat bout when u go to the track to go down the quarter what would u guys put it on then?

[sky30]

I run 24-26 psi cold on the street with 225 45 17 tyres, have had no problems with wear, and traction is lots better than with 30+ psi.

[croat]

33psi on street approx

[Busky2k]

If you have traction problems lower them to mid 20s cold. Handling will suffer however.

[KRiMiNaL]

sorry guys wats cold mean?

[Brackez]

Means before driving the car, ie. with cold air in the tyres. As you drive around, even normally your tyres heat up. Boyle's law dictates that when this happens, the pressure of the air in your tyres goes up too. Hence you will get different results if you check your pressures b4 & after driving (higher reading when hot).

[Duncan]

40-44 hot firms the tyres up nicely. Cold is too damn hard to do unless you have a compressor in the garage

[xRHETTx]

40 psi hot. Thats what they said at the advanced driving course was good for handling in the dry and in the wet.

[Angry]

any particular reason u want to risk failure exceeding the design specification of a tire loading?

[KRiMiNaL]

so if i want 30psi cold, how much pressure would i need if i drove to the servo to fill up? (tyres would be hot)

[Brackez]

Not actually sure what the differences would be, I suppose it would depend on how far away the garage was, speeds travelled at to get there etc.

Best way to set them cold would be to get a tyre pressure gauge (not too expensive for the simple pen type ones), then let them down progressively at home till you get the cold pressure you're after .

[djr81]

32PSI cold...

For those that want to do some circuit work you can (to a degree) dial in a lesser/greater amount of understeer/oversteer by changing the tyre pressures. To make the thing understeer drop the pressures are the front. To lessen understeer increase the front pressures. You should be able to easily detect a 2psi change tested back to back.

Higher pressures will reduce a tyres slip angle - limited at the top end by the tread face crowning.

Lower pressures will increase slip angle, but provide a better tractive force. Unfortunately low tyre pressures will kill your tyres quicker than most other things (burnouts aside) & cause problems running at high speed due to heat build up in the carcass.

In short look after you tyres by keeping the pressures right (go buy a $10 gauge) & rotate them after any track days to equalise wear. The outside front after any track day will look pretty ordinary.

[madmurf]

any particular reason u want to risk failure exceeding the design specification of a tire loading?

What The!

The most miss understood bit of information ever printed is the Tire Recommended Specs.

The manufacture put recommended tyre pressures to have a average Jo Blo sedan have a soft ride.

The max pressure warning is for the septic tanks (Yanks). Its part of the USA design rules that all tyres in the USA must have a max tyre pressure rating.

It has nothing to do what you can actually run the pressures at and what you should run them at.

For drags go soft under 30 psi. For good handling, tyre life, economy and less chance of a tyre blow out go for min 38.

Go ahead and run at the tyre manufactures spec he and the local tyre shop will appreciate the business in tyre sales.

Cheers

[Sheriff Wan]

:werd:

38+ for cold tyres unless u want to use alot of petrol and loose all of ur handling!

[xRHETTx]

What The!

For good handling, tyre life, economy and less chance of a tyre blow out go for min 38.

Cheers

BINGO! Thats why.

[Angry]

u see .. i come from a speedway back ground ....at most my tire pressures are 20psi on the right rear on a 10inch wide tire....a realm were sidebite rules .. hence the pressures being as low as 12psi on the left rear ..to induce sidewall flex...but thats not really what i'm trying to make a point about...anyways

over inflating to me ....can cause a tire dislodging from the bead on the rim from lateral loading.. .. over inflating to the point where ur tire balloons the tread ..which is basically the levels ppl are suggesting in the latter of this post , gives you a lesser and much narrower contact patch on the road....unsafe and totally not needed. tire wear rate doesnt change if u run 30 or 50psi ..just the amount that gets worn does from driving friction ..i'd rather burn the entire width of a tire up ..than just a bit in the middle. u need a certain amount of give in the tire thru its pressure is a nessecity.. driving with stonehard pressures doesnt give u any.

on my coupe i run 32psi cold all round at the very most. on at the moment 205 60 tire.

anyways thats just my opinion on the matter.

Matt