Tyre pressue

Standard and aftermarket Wheels and Tyres

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marcus
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Tyre pressue

Post by marcus » Mon Jul 28, 2014 12:02 pm

I have a 1985 Mk2 GTL with the standard 13" tarantula alloys, shod with Continental EcoContact 3 tyres (175/70).

For years I've been running the fronts at 35psi and the rears at 30, because when inflated to the recommended pressure (26psi) shown on the sticker on the B post, they look under-inflated, and presumably that advice was for whatever tyres the car originally came with.

Anyone got any thoughts on what the 'correct' pressure is for these tyres on that car?


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Nate
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Re: Tyre pressue

Post by Nate » Mon Jul 28, 2014 1:48 pm

Correct pressure should be on the sticker. Do your tyres wear round the middle faster than at the edges?


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Re: Tyre pressue

Post by ianaudia4 » Mon Jul 28, 2014 6:01 pm

Yep, the tyres should be inflated as recommended. The sticker only shows the size of tyre (and whether fully loaded) not the brand!


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Re: Tyre pressue

Post by the edmundator » Tue Jul 29, 2014 8:07 am

They should bulge slightly in the tyre wall towards the bottom of the tyre. In truth, there are a variety of factors that affect optimum tyre pressure and there isn't really one correct pressure. However VW's test drivers will have spent quite some time establishing the optimum pressures for general road use. For road tyres, advice is usually to set the pressures when the tyres are cold. Ambient air temperature will affect pressures, so if it's cold you might need more air or vice-versa.


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marcus
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Re: Tyre pressue

Post by marcus » Tue Jul 29, 2014 2:25 pm

One of the factors I'm concerned about, is that tyre technology has advanced somewhat in the 29 years since my car was built, hence me thinking the recommended pressure may no longer be appropriate given my perception of under-inflation... :(


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Re: Tyre pressue

Post by the edmundator » Wed Jul 30, 2014 1:01 am

Part of the problem is that modern cars run with much lower profile rubber, so we aren't used to looking at big tyres so much these days. They will probably look a bit flat, but the manufacturer's pressure will be right, regardless of the tyre - it's not like you're replacing crossplies.


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Re: Tyre pressue

Post by Nate » Wed Jul 30, 2014 9:30 am

So have your tyres been wearing more in the middle than the edges?


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Re: Tyre pressue

Post by marcus » Wed Jul 30, 2014 9:44 am

Wear has been pretty even as far as I can tell...


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Tim_R
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Re: Tyre pressue

Post by Tim_R » Wed Jul 30, 2014 3:06 pm

I found that 29psi in the front tyres when they were the 185 60 14 size worked better for me than the 26psi. The car had more front end grip and better turn in. Over that pressure reduced the grip again and gave a harsher ride as there was less give in th tyre. Interestingly VW's own recommendation for the mk2 Golf is 29/26 front/rear with 1-2 people in and there's not much difference in weight between the two.


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Re: Tyre pressue

Post by DannyH » Wed Jul 30, 2014 3:24 pm

My Scala I is marked at 29 front and 26 rear.

I usually just put 30 in all round as there's usually stuff in the boot.


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