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View Full Version : Factory Tyre Pressures wrong?



mpau009
02-10-2006, 02:43 AM
As per the title???

When i had some factory-size GS-D3 goodyears (205/55 r16) fitted to my Legnum a couple of months back, the people doing it put them at Mitsi recommended pressures according to the sticker on the door F32psi, R29psi. Ever since then my car has handled like crap:( They told me at the same time that my 3 out of 4 shocks are leaking, so i assumed this was the cause, and it certainly doesnt help.

The symptoms were that the back of the car seemed really unsettled, like the rear wheels reacted a second after the fronts, if i swerved side to side, it felt like the back was skiing along. Also the AYC has been really twitchy.

Today i put 35/35 psi front and back, and it seems to be much better.

What is everyone else running? I cant quite believe the difference it has made. (shocks still need doing real soon tho..) I'd be keen to hear some other experiences.

Kenneth
02-10-2006, 02:58 AM
I have always run between 34PSI and 36PSI, usually 36PSI

they are fairly heavy cars and as such requre reasonabe tyre pressure.
I also found that the GS-D3s had soft sidewalls and the car tends to get sideways movement from that. (ie you can rock the car when stationary)

Still, they grip well and are predictable.

If your shocks are buggered, I would get them sorted too... should also make a mile of difference.

KiwiTT
02-10-2006, 03:41 AM
Around Town I have 38 Front and 36 rear. Just feels firmer and more secure.
On the open road for hard driving, I drop it slightly to 36/34, the pressure may increase slightly under load, and too high a pressure makes it feel as is you are on marbles, especially when going over chipseal.

Subaru ETA
02-10-2006, 06:11 AM
i run 36psi. you will find that the factory rec is for a soft nana ride... like for example the ford territory rec is 32psi. 32psi one a huge suv tyre is just stupid and they wear quickly how ever it just makes the ride softer

Spirit
02-10-2006, 08:00 AM
34psi all round for me for daily driving /Wyhy

Kieran
02-10-2006, 08:25 AM
I run stock pressures with no apparent issues on standard rims and tyres. However I haven't experimented with other pressures to see if there's a difference.

I'll have a play when I've resolved a couple of minor issues with my suspension setup.

Axeboy
08-10-2006, 10:43 PM
Ive got mine set at 32 all round, car runs fine although ive noticed it to be a little uneasy at higher speeds, not sure if thats tyre related but i might up them to 34 all round to see if it makes a difference, either way.

jaimz
09-10-2006, 01:50 AM
Hmmm, I've always done 33 all round, but never thought too hard about it. /Hmmm

d i c k i e s
09-10-2006, 06:22 AM
me either... well im not too fussed bout it on my legnum as i feel it handles pretty good (could handle a lil better, but doesnt help when you dont have enought rubber on ya wheels. hahaha). My Galant has at least 36psi all round. just cos i feel it wobble a lil bit.

bradc
09-10-2006, 08:35 AM
From what I've read, GSD3's have a fairly soft firewall, so they maybe a little too soft if you run them at the factory pressure. I run mine at 36 front, 34 rear with 235/45/17 GSD3's and haven't had any handling problems

jaimz
09-10-2006, 08:44 PM
Brad, interesting you say that about the GSD3s...
Bek and I went to Coromandel last weekend, and after a weekend of cornering (just on the limit of acceptability for a pregnant passenger :curtain:), I noticed scuff marks 'n stuff on the tyres well down the side walls.

OSiRiS
09-10-2006, 09:58 PM
Brad, interesting you say that about the GSD3s...
Bek and I went to Coromandel last weekend, and after a weekend of cornering (just on the limit of acceptability for a pregnant passenger :curtain:), I noticed scuff marks 'n stuff on the tyres well down the side walls.

Remember a while back I made a post on how rooted my GSD3s were after a jaunt down to Thames and back the "scenic" route?

Kenneth
09-10-2006, 10:01 PM
Brad can attest to the fact that they wear, i put a fair amount of wear into mine on a wellsford run. however at 36psi all round the sidewalls were still fine.

if you have sidewall scuffing, you eithier have something wrong or you have been touching kerbs ;)

OSiRiS
09-10-2006, 10:03 PM
I've gone through my set of GSD3 in less than 1 year.

bradc
09-10-2006, 11:12 PM
yeah if there are marks on the sidewall then your pressures are too low. Were the marks similar on the front and rear tyres, or were they worse on the fronts? Put another couple of psi in them and see what happens.

Lucas
11-10-2006, 06:14 AM
I run 36 front and rear on 40 profiles. Seems fine but the outer edge of my rear tyres are rounding off quite noticably and I only sometimes do hard cornering. They're cambered a couple of degrees so it seems strange.

Now I have a question... who here thinks that the tyre pumps at gas stations are accurate? I prefer using the digital ones rather than the stupid analogue ones. If I use the same pump each time my tyre pressures are exactly the same as when I checked them last. If I go to a different station then it may say they're at 33psi or 38psi when I know for a fact that my tyres don't leak.

Anyone know of an 'accurate' pump?

bradc
11-10-2006, 07:05 AM
I doubt any at gas stations are accurate. It seems strange you're running such high pressure at the back, normally you would run slightly higher pressure at the front because of the higher weight at the front.

It is even stranger that the outer edges of your tyres at the back are getting worn when you have camber on them too, I assume it is a couple of degrees this way / \ and not \ /

Maybe you should get your alignment checked out, and get them to fill the tyres exactly to the pressure you want them to run at, I would suggest 36psi at the front and 34psi at the rear as a good setup if you are running 45 or 40 profile tyres.

Lucas
13-10-2006, 04:59 AM
Yeah it's / \

I run 36psi because the outer edge wear isn't so bad. I got an alignment done for that problem as well but it didn't seem to make any difference (I think they did a poor alignment anyway because the before and after stats had bugger all difference so maybe it is still an alignment problem)

I'll leave it for a while anyway as I need new brake pads and skimmed rotors not to mention a possible wheel bearing change. Do it all at once and be done with it me reckons!

MidnightSun
14-10-2006, 02:06 AM
Always run 34psi all round - less than that gives noticeably poorer handling on my 18" GSD3s, esp in wet.

ANTHONY
14-10-2006, 07:01 PM
i'm running 215x17 so will they also be 36-34?