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Old 06 August 2012, 02:41 PM
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R2D2
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Default Tyre Pressures

Ok - This is my first post for my new car.

I'm pleased to say that LOVE my new Classic WRX and will never look back.
Good riddance to the old 06 SportWagon with all its electrics problems.

The reason for my post is that I want to ensure that I do everything possible to keep my car in the best condition possible - Fluid Levels, tyre pressures etc.. so that its runs as best it can.

Can anyone advise the optimum tyre pressures for the following tyres?
Yoko Prada Spec2 - 215/45/ZR17 (on all 4 corners)

These are the tyres that were on the car when I bought it and looking at ££'s they are not that cheap, are these the best ones for the car?
Which others would be as good if not better (for the money or cheaper).
Old 06 August 2012, 02:49 PM
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joz8968
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Std. pressures are, IIRC, 36psi front, 32 rear (or it might be 35f/31r). You might still have the sticker on the slam panel for the drivers door - go check (sticker is below the lock striker).

Use same pressures (when tyres are cold).

Then experiment up or down from there for best feel and/or handling. Whatever gives you most confidence...

Last edited by joz8968; 06 August 2012 at 03:51 PM.
Old 06 August 2012, 03:01 PM
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The car has been completely re-sprayed so no stickers anywhere - plus the car is a gray import so the chasis no doesn't bring anything up when I put in anywhere.

I'm currently at 31 psi at the front and 30 at the back

I'll try it higher and see if it makes a difference - excuse my ignorance but will the weather have an impact on what pressure I should set them too? (wet or dry roads)
Old 06 August 2012, 03:08 PM
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The barometric pressure won't have a noticeable effect - so forget that.

Lower profile tyres usually dictate a slightly higher pressure than OEM to be used. So perhaps try +2psi all round (or maybe +4), over OEM.

Defo don't go too much lower than OEM pressures on the lower profile tyres, as you'll wear the edges quicker than the centre, and they may heat up too much, which may lead to deflation when hooning. And you'll also suffer poorer fuel cons. (which, on a Scoob, you defo don't want! )

Conversely, too higher pressure will wear the centre quicker than the outsides, and the handling will feel a bit skittish (due to lack of optimum grip).

As said, set to about 36/32 (and then experiment around that, if required).

Last edited by joz8968; 06 August 2012 at 03:17 PM.
Old 06 August 2012, 03:24 PM
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>>Std. pressures are, IIRC, 36psi front, 32 rear (or it might be 35f/31r).<<

>>Lower profile tyres usually dictate a slightly higher pressure than OEM to be used. So perhaps try +2psi all round (or maybe +4), over OEM...<<

So..sorry, are you suggesting to increase them to 33 front / 32 rear (+2 from where they are now) + 2 over the std 35 front / 31 rear?
Old 06 August 2012, 03:44 PM
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Start from std pressures (not what's in there at the mo.)

Last edited by joz8968; 06 August 2012 at 03:51 PM.
Old 06 August 2012, 03:47 PM
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Thanks for spoon feeding me there - I'll give them and extra few puffs on the way home and see how she goes later.

Thanks again.
Old 06 August 2012, 03:51 PM
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...Just been out to my own STi 5 to check the sticker:-

It's 2.3bar (33psi) front; 1.9bar (28psi) rear...
Old 06 August 2012, 03:55 PM
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ok.. in which case... I'll try 35 front and leave the back at 30.... sound like a good idea?
Old 06 August 2012, 04:02 PM
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See how you get on at std first (not that 2psi should make a huge diff anyway).

But if you start at std, then you always have a baseline control to compare against.
Old 06 August 2012, 04:35 PM
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I've just checked them at the garage and my manual gauge is clearly out.. they were at
29 on the front and 27 at the back.
I've just increased them to 35 on the front and 31 on the back.
I'll drive it for a day but I think they may be a little too hard... great on the straights but the back bounces out a bit on bumpy corners.
Old 06 August 2012, 06:20 PM
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Originally Posted by joz8968
...Just been out to my own STi 5 to check the sticker:-

It's 2.3bar (33psi) front; 1.9bar (28psi) rear...
Yes that.s the pressure i use except my tyres are 235/40/18. My advise to the OP is to get them nitrogen filled rather than air.
Old 06 August 2012, 09:08 PM
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Minimal benefits on 100% Ni. Air has 78% of it in it anyway, so I wouldn't bother with the 'hassle'.

But if he's hell bent on fine tuning his pressures/stabilise them, then yeah, every little helps...
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