MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: Gmac on April 21, 2016, 03:13:15 pm

Title: Tyre size question..18"
Post by: Gmac on April 21, 2016, 03:13:15 pm: Quick question...

I'm planning new putting H&R lowering springs on and also putting a set of 18" wheels on which are 8j wide..

They come with 235/40/18 tyres... I know normally we'd be looking for 225, but will the 235 cause any rubbing issues????

TIA
Title: Re: Tyre size question..18"
Post by: pudding on April 21, 2016, 03:39:35 pm: It might throw the speedo out a little as the sidewall height is a percentage of the width.
Title: Re: Tyre size question..18"
Post by: jayha11 on April 21, 2016, 03:58:59 pm: Few things that will help:

Whats the offset of the wheels?
Are the springs 30mm drop?
Title: Re: Tyre size question..18"
Post by: Gmac on April 21, 2016, 07:10:37 pm: Quote from: jayha11 on April 21, 2016, 03:58:59 pm
Few things that will help:

Whats the offset of the wheels?
Are the springs 30mm drop?

The offset is et43, and the drop is indeed 30mm...
Title: Re: Tyre size question..18"
Post by: jaffa on April 21, 2016, 10:21:18 pm: Probably rub with the 235's
Doing the screw mod will give you a few mm's clearance but you should get some 225's

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Title: Re: Tyre size question..18"
Post by: sub39h on April 21, 2016, 10:37:33 pm: Quote from: Pudding on April 21, 2016, 03:39:35 pm
It might throw the speedo out a little as the sidewall height is a percentage of the width.

I do agree that you should run the right size tyre, but the difference is negligible - 4mm radius or less than 1mph difference at 70mph

http://www.brspecialtuning.co.uk/Tyre%20size%20calculator.htm
Title: Re: Tyre size question..18"
Post by: jayha11 on April 22, 2016, 10:44:15 am: Quote from: Gmac on April 21, 2016, 07:10:37 pm
Quote from: jayha11 on April 21, 2016, 03:58:59 pm
Few things that will help:

Whats the offset of the wheels?
Are the springs 30mm drop?

The offset is et43, and the drop is indeed 30mm...

Just to give you some perspective I am running the following...

18x8j ET35 (stick out 8mm further than yours)
lowered approx 65mm front & back
Tyre's are 215x40x18 to aid with tucking at the rear

Is there a specific reason you want to run 235 tyre's?
Title: Re: Tyre size question..18"
Post by: Gmac on April 22, 2016, 11:27:12 am: Yeh, the wheels that are for sale come with 235's. I've currently got 17" wheels and tyres.
Title: Re: Tyre size question..18"
Post by: Gmac on April 22, 2016, 11:27:59 am: Quote from: jaffa on April 21, 2016, 10:21:18 pm
Probably rub with the 235's
Doing the screw mod will give you a few mm's clearance but you should get some 225's

Sent from my iPhone using Tapatalk

Will do a search for the 'screw mod'. :happy2:
Title: Re: Tyre size question..18"
Post by: pudding on April 22, 2016, 11:59:43 am: Quote from: sub39h on April 21, 2016, 10:37:33 pm
Quote from: Pudding on April 21, 2016, 03:39:35 pm
It might throw the speedo out a little as the sidewall height is a percentage of the width.

I do agree that you should run the right size tyre, but the difference is negligible - 4mm radius or less than 1mph difference at 70mph

http://www.brspecialtuning.co.uk/Tyre%20size%20calculator.htm

Yeah it's very minor usually, but sometimes one tyre maker's '235' is a bit different to another's. I usually find taller tyres than standard affect the gearing and unsprung mass more than anything else though!