tyre pressure for 225/40/18. (I know there's a thread but its 7 yrs old now!

[Markus74]

As title. Just wondering. There's an old thread but the answers didn't look conclusive. Only started thinking about tyre pressures as I've just been out giving the car some beanz adjusting boost. Thought I'd see what the garage had filled rears with (new tyres last week in rear) and was horrified to see they'd put 40psi in them. Now the back has been twitchier but I put this down to the recent addition of locking subframe collets, also had better mpg...... But....40psi!!!!!.
Always ran 32psi front and rear before.
Any ideas?

[Mark]

Pretty much always run 28 front and 30/32 rear on any road car.

[sam721]

I run 32 front usually and 40-45 in the rear with a welded diff

[Markus74]

Pretty much always run 28 front and 30/32 rear on any road car.

Trying 32 front 34 rear now

[Markus74]

I run 32 front usually and 40-45 in the rear with a welded diff

40-45! Bloody hell that must feel uber twitchy at the rear!?

[Slamz]

I ran 40psi in the rears daily for ages, not twitchy at all, was very planted actually!

[Markus74]

I ran 40psi in the rears daily for ages, not twitchy at all, was very planted actually!

How did they wear mate?

[Slamz]

They wore evenly. Quite fast though but that's due to my driving 'style'

[Markus74]

They wore evenly. Quite fast though but that's due to my driving 'style'

Had 'issues' getting traction down when giving the big right foot when my rears were at 40psi lol, can see why they didn't last you long

[Slamz]

I didn't have issues getting power down, only stage 1a though, only went when provoked

[Markus74]

I'm also only 1a mate, plus a mani it does seem to be feeling particularly pokey though recently. Good job sr20s aren't like pintos, they used to go real well just prior to going bang

[jackm]

Gunna wait for the slating on this but my golf says 41 for that size tyre.

For a 200 I'm not sure as it's a different style of car with different weights.

[Markus74]

Gunna wait for the slating on this but my golf says 41 for that size tyre.

For a 200 I'm not sure as it's a different style of car with different weights.

Hmm a lot of other car forums (bmw, Vauxhall etc) also swore by big psi for the same size tyre weird

[jackm]

I was surprised with it, ran 36 front an rear in my 45 profile 18's before. Good grip and wore evenly (bar camber on front).

Id say it was a good pressure, might be worth trying it out or around 36-40. what id do

[Markus74]

I was surprised with it, ran 36 front an rear in my 45 profile 18's before. Good grip and wore evenly (bar camber on front).

Id say it was a good pressure, might be worth trying it out or around 36-40. what id do

Think I'll experiment over the rest of the week

[Slamz]

I'm also only 1a mate, plus a mani it does seem to be feeling particularly pokey though recently. Good job sr20s aren't like pintos, they used to go real well just prior to going bang

Cold weather, so it should be loving it and going very well! Check for boost leaks etc. if it feels down on power, I've just put mine back together, and even though I'm trying to stay off boost, it really feels like it wants to go in this weather!

[Markus74]

Cold weather, so it should be loving it and going very well! Check for boost leaks etc. if it feels down on power, I've just put mine back together, and even though I'm trying to stay off boost, it really feels like it wants to go in this weather!

Defo no boost leaks now, smoke test last Saturday showed one which Polo sorted. Yeah cool air defo making car go like the clappers lol

[sprint]

Iv always stuck around the standard pressures for the car regardless of how much bigger the wheels are. Never had any issues with tyre wear

[sam721]

40-45! Bloody hell that must feel uber twitchy at the rear!?

I drive it daily so im very used to it. Its a little twitchy sometimes but i like it, Tbh i would run like 32 in the rear but i like the way i can throw the car around sideways easier with a little extra pressure. Plus it makes parking/turning tight with the welder a bit better