Tyre Pressure for 215/35/18R

[Warren]

Hey all,

Just wondering what tyre pressure any of you would recommend for a GT-T with Goodyear 215/35/18R Eagle F1 tyres.

Thanks.

[skoty]

At my old work we wouldn't run anything less that 34 psi in low profile tyres. So 34-35 would be a good figure.

[B_giB]

I wouldnt run anything lower than 36 psi all round on 18's, possibly even 38 running such a low profile tyre on a heavy car

[barryogen]

At my old work we wouldn't run anything less that 34 psi in low profile tyres. So 34-35 would be a good figure.

I wouldnt run anything lower than 36 psi all round on 18's, possibly even 38 running such a low profile tyre on a heavy car

Hmmm, Just hi-jacking the thread somewhat... does that mean that in my 205/40/16s I'm running it too low at 24-28 depending on load? Garage suggested 26 average from memory.

And If I were to go to say 215/35/16s would it mean I should change to a higher pressure?

And can someone explain why?
I would have thought with a shorter wall they wouldn't need as much pressure, let alone a higher pressure.

[B_giB]

DUDE!!! if you are running your tyres that low you will get cracks on the inside sidewall!!!

Now regarding the pressure with low profile tyres, the air pressure holds a majority of the load, then the sidewall, so the less sidewall, the more pressure needed. The more load carried the more pressure needed.

And who ever your mechanic is that said you should run 24-28 psi should be shot, Its not a wheel barrow.

Most car manufactures recomend 28psi for normal load on standard wheel tyre package, Which I reckon is still to low, I run 36-38 in my Merc (205/60-15) which is 1400 kg i think, tyre placard recommends a MAX of 31 psi with max load. I usually reccomend 34 psi for standard wheel and tyre packages, depending on how the vehicle gets driven, increase pressure if you are going to be driving in a "spirited" manor. also increase if you are going to be increasing wheel size/ going to a lower profile tyre.

[postfach]

Most car manufactures recomend 28psi for normal load on standard wheel tyre package, Which I reckon is still to low, I run 36-38 in my Merc (205/60-15) which is 1400 kg i think, tyre placard recommends a MAX of 31 psi with max load. I usually reccomend 34 psi for standard wheel and tyre packages, depending on how the vehicle gets driven, increase pressure if you are going to be driving in a "spirited" manor.

Spirited manor? is that like a haunted house? (just joking ) but IMO 36-38psi seems way too high for a 60 profile tire. I bought a set of batty rims (225/50r16) a few months ago and put them on my car without checking the tire pressure, I drove it for about 10 minutes before deciding that something was amiss with the tires (which were near new, and a fairly decent pattern and compound), cornering grip was poor and straight line traction was bad (wheels would spin in 3rd gear....).

When I got to the gas station they were all on 40psi. I took it down to 30psi and it was MUCH better, grip was improved in all aspects.

Yes low profile tires need higher pressure, 36-38 sounds reasonable for something like 35 profile.

Remember the harder you drive, the hotter your tires get. As the tires heat up, the pressure inside increases. Cold tire pressure should always be a few psi below the desired pressure while driving.

Too high pressure = bad traction, increased road noise/vibration, undue wear to the center of the tread
Too low pressure = bad traction, undue wear on the outer areas of the tread (and if it's really low, the sidewall)

I agree that if you're just driving the car for the sake of getting somewhere, then a lower pressure is better, as you get less road noise and don't feel the bumps so bad, somewhere around 26-28psi for a higher profile tire, 34-35 for low profile (can't really get rid of road noise with low profile tires though)

For spirited driving, then experimentation is the key, but definitely don't increase more than a few psi over regular. The manufacturers have been putting wheels on cars for many years, chances are they have a fairly good idea what they're doing

[Brick]

yep real low profile as in 45/40/35's - 36-38psi
50/ 55''s- 34psi
normal tires- 32psi
4wd tires - 36psi

[B_giB]

You actually get more road noise from running to low pressure, as the sidewall is basiclly crinkling when rolling along.

I allways run 38-42 psi in 4wd tyres.

All of the cars I drive and put tyres on I run at least 34 psi.

[barryogen]

wow guys... thanks... will check it on the way home.

I guess my head has been stuck in the time(~10 years back) when I used to drive my hillman with 185/60/13s... man it was awesome.