Max Psi?

[Ericjayrol]

Hey, Im sorry if this sounds like a really stupid question that anyone with a license should know, but I have just never been sure.

When your tyres say 55PSI Max press, does that mean it would be best for me to fill it to 55? Or does it mean thats just the max it can handle, but I should be putting in 50?

Or am I way off and theres an ideal PSI such as 43 for certain sizes or something like that?

I know your tyre pressure has an affect on petrol consumption, but im also told that your tyre pressure can have a HUGE impact on your speed and acceleration, so I was wondering about all this.

Thanks for any answers

[C4NC3R]

That's the max they can handle, not the max you should pump them to.

In general, for 17/18/19' rims, I go for 34-36 PSI, that's what we put in as a standard at Beaurepairs.

[Ericjayrol]

Thanks heaps Cancer...

I'll keep my 34 at the 36 mark then.

[some_cs_student]

What tyre profile? Lower profile often means higher pressure, within reason

On the 65 profile I run 36psi cold.

On the 40 profile I was recommended 38-40psi cold.

[Ericjayrol]

they're just the stock tyres, so im gonna assume the figures that cancer gave were right under that assumption?

[some_cs_student]

  Ericjayrol said:

they're just the stock tyres, so im gonna assume the figures that cancer gave were right under that assumption?

I was recommended 38-40psi on 235/45/17 if that helps, 40psi was for an advanced driving course at Sandown, but everyone seems to recommend a slightly different amount so you will have to experiment

[Birds]

Experiment mate, but always gauge it on the tyre profile rather than wheel size.

With standard tyres anywhere from 32-36 will be fine. Low profile (35/40) anywhere from 38-44 is not uncommon.

When you get to know more about it, you will use different pressures for different situations. A good test you can do is to inspect the tyre wear after some time...if you have too much wear on the sides of the tread it means your pressures are to low, too much wear on the centre of the tread and your pressures are too high.

[Ericjayrol]

Thanks heaps CS student & Birds.

That helps a lot, i'll try em at 36 and see what results I get.

[Mangune]

I put 36-38 in 45 profile tyres. I got recommened that from my brother (works at bob jane)

Play with it to see what you like

[bubba]

On my old 225/50/16's I ran ~36psi cold, the 235/45/17's I ran at about 40-42psi and I've found my 235/40/18's like 45psi cold.

[Ten Four]

Lol, on my previous 33gtr i ran 50psi all round... Don't ask me why, just did. They were cheap arse china tyres tho so I could oversteer at anytime I wanted...

Currently, I run about 40ish psi.

[Ericjayrol]

Thanks for the detailed explanation Bubba.

Thank you all for listing what your running on certain profiles, it helps me get a good idea on the averages

[BeEnAr]

There is quite a bit of info on this around the web, a lot of people state the best tyre pressure for your tyres in terms of performance, wear and comfort is the MAX pressure stated on the sidewall of the tyre minus 10%. So under that assumption it would be 55 - 5.5 which is 49.5PSI. That seems a bit high for me, I would stick to between 36-40 PSI cold pressure.

[Ericjayrol]

Thanks Beenar, That helps, does anyone else agree with/heard of the 10% theory?

[GTS4WD]

WOW!

Are you guys serious?

I run 45-50psi on the rears at the track when I go drifting.

And about 32-34 at the front

(16" rim, 205-55)

It depends very greatly what press to run.

Factors like wheel alignment, driving style, driving conditions, quality of rubber and what you want to get out of your rubber.

Have a look at the tyre wear on the rubber, where is it wearing first? Is it an even wear? Is it feathering on the tread blocks?

For daily driving I wouldnt recommend more than 36 just to try limit fuel consumption.

Tyre press is a comprimise betwee grip and tyre wear. Do you want you rubber to last? or do you want it to grip?

[PM-R33]

Lately i've been running 33-35psi in the rear to get more grip on 255/35/18 (used to run 38psi). Seems to hold second on full throttle a lot better with only minor wheelspin now.

[Ericjayrol]

I want grip mainly, and I do ask these questions to get answers for both daily drive and track performance, because I drive it as my daily driver but also want to get into track soon.