17" Tyre Pressure??

Anonymous · January 14, 2009, 20:01

I've searched but cant find any info on tyre pressures other than standard size wheels, I've got 205 40 17 on front and rear, what should the pressures be?? the garage that fitted them said they should be 2psi more than standard, and then said they had set them at 35 front & rear!!! So I dont have any faith in the garage, should'nt the pressure be same as standard (26F & 32R), I cant see how the size of the tyre matters to pressure, any help please

MR2 New Boy · January 14, 2009, 20:17

I have mine at 28 front and 32-34 on the rears.

BE aware that your rear tyres should be wider than your fronts!!

Peter Wright · January 14, 2009, 20:23

Having had my 17" for 6 years now and a couple of mishaps at 26-28, tried various over a 6 month period until I felt happy at 32-34, but different tyres will not act the same, especially depending on the strength of the tyre wall, best thing to do is try various until you feel happy
Pete

muffdan · January 14, 2009, 20:27

please, get your tyre size stagger back! The car is not safe to drive with same size tyres front and rear. Plenty of info on the subject to be found with the search function!

Jason

evileye_wrx · January 14, 2009, 20:31

I've had mine at stock settings for 2 years and never had any bother with them.

As has been mentioned once you should still have rear tyres 20mm wider on the back than the front. The car is designed to run like that and is otherwise unstable. There is much info on this site to back this fact up. I'd look at changing either back or front as soon as possible.

Phil

VVT-i · January 14, 2009, 20:57

I'm running 25psi front and 29 psi rear.. I'm useing Toyo T1-r and find the handling perfectly ok for how I use my car, I've got 205/40x17 on the front and 215/45x17 on the rear.. not quite the correct stagger as Ideally I would have 225/40x17 on the rear... but no-one I know makes them and I'm not sure if I'd get away with 225/45x17's or not... will check fitment when I'm due rear tyres.

Anonymous · January 14, 2009, 21:28

Got quite interested in this. Quote one 'boffin' on the web as follows: 'Technically, when you go to a larger/wider tyre with a larger/wider/longer contact patch, the tyre pressure can actually go down a bit as the weight of the car is now being transferred to the ground over a greater area.
By maintaining the same, or higher, pressure as the smaller tyre the car benefits from a more stable contact patch and the tyres are less susceptible to deformation under load'. Also, 'More pressure is like stiffening the suspention'.
I interpret that as something like - less pressure will give more traction than before and that more pressure will give better cornering. He also talked about the need to experiment (at this point the disclaimer comes into play). Safe option, or starting point seems to be start with the same pressures as the standard set up.

roger · January 15, 2009, 14:10

I would guess that everybody here has a front / rear stagger, so any info won't probably apply to you. Having said that, ask 10 owners with same size tyre and you would probably get 10 different answers. The tyre itself will influence this e.g. stiff or supple side walls.

So the real answer, is go and try, but be careful doing it.

Carbibles.com has good section on wheels / tyres....and just to add to sandstrain's post, they provide the contrary opinion

Quote from: "carbibles.com"If there's one question guaranteed to promote argument and counter argument, it's this : do wide tyres give me better grip?
Fat tyres look good. In fact they look stonkingly good. In the dry they are mercilessly full of grip. In the wet, you might want to make sure your insurance is paid up, especially if you're in a rear-wheel-drive car. Contrary to what you might think (and to what I used to think), bigger contact patch does not necessarily mean increased grip. Better yet, fatter tyres do not mean bigger contact patch. Confused? Check it out:

Anonymous · January 15, 2009, 18:25

Thanks for the replys, will try them at standard, and as for loosing grip in the wet in a rear wheel drive car............have I got experience in that department, I'm now a proud owner of a MR2 due to the fact I wrote-off my Porsche Boxster on the same day I bought it, horrific rain conditions, standing water on a roundabout with a notorious camba, you can guess the out-come. No-one was hurt though, except my insurance company - as I had only been insured 2-hours before the accident. So I'm sure you'll recognise me in my blue 01 taking round-a-bouts at 2-3mph. lesson lerned.

Anonymous · January 15, 2009, 18:28

Get that stagger back on your tyres, or it will be round two.

Liz · January 15, 2009, 18:30

Friendly warning - Please ensure that you get the stagger sorted out - correct tyre pressures won't save you!

EDIT - Nelix and I posted at the same time!! Hopefully you get the message! s:D

s:D s:wink: :wink: s:wink: