MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: john_o on June 16, 2009, 04:37:37 pm

Title: increasing the tyre width .....
Post by: john_o on June 16, 2009, 04:37:37 pm
GTI Edition 30

standard is 225/40/18 XL

the easy option is to stick with this , but just for fun (I blame jonnyc for this...) I looked at 'options' using the tyre calculator at http://ejelta.com/

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Flh3.ggpht.com%2F_f42ZbKWLXUk%2FSje7FaQyq-I%2FAAAAAAAAAqw%2FU9Xs_cRIa8s%2Fs800%2Ftyres.jpg&hash=57bf1ab6f1f6a89a0181193089cf2ba64f54e6c5)

So I could run 255/35/18 or 265/35/18 quite easily, and I checked and at least Goodyear F1 Asymmetric are available in both these sizes...

Worth a punt ?
or just ruin the GTI setup/balance???
is there enough space on a std car to do this???
mmmmmmmm
Title: Re: increasing the tyre width .....
Post by: mortygttdi on June 16, 2009, 05:26:37 pm
Not quite sure you would be able to run any thing wider than a 245 with the risk of sidewall failure and also the risk of the tyre rubbing on the shock/spring I think a 265 would be very over the top any way and you wouldn't see the benifit to say a 235/40, Also if your running a set of pescara's are they not 7.5 wide cos that would limit your tyre choice down to a 235 at max? I might be just talking a load of BS but on my previous Focus ST225 I was running 235/40 on that and it stuck to the road like muck on a blanket.

Darren
Title: Re: increasing the tyre width .....
Post by: Hurdy on June 17, 2009, 01:01:11 am
There are a couple of cars in the USA running 255 section rubber. It is possible, but you need to run a fair amount of camber to clear the arches, plus you'd need 8.5" wide alloys to fit safely. :smiley:

Jonnyc is running 235 section R888's which he measured at 240+mm for tread width.
Title: Re: increasing the tyre width .....
Post by: john_o on June 17, 2009, 11:02:05 am
cheers guys , so the rim width and clearance are an issue  :happy2:

Im wondering whether to go to 235/40/18 as every little helps BUT Im worried about the difference re triggering my ESP as Im only changing the fronts.
Be nice to try something different though.
Title: Re: increasing the tyre width .....
Post by: tony_danza on June 17, 2009, 11:04:29 am
Whilst a wider tyre on a small rim may improve traction, I'd be worried about how the sidewall performed on cornering - I could see it rolling a fair bit.
Title: Re: increasing the tyre width .....
Post by: john_o on June 17, 2009, 11:10:29 am
indeed tony, with the 235/40 this concerns me (as the ratio hasnt changed).
however with the 255/35 if you can get it to fit its virtually identical to the original tyre for sidewall height.

what do you run on the track?
Title: Re: increasing the tyre width .....
Post by: tony_danza on June 17, 2009, 11:27:29 am
It's not the height so much, more the angle of the tyre wall. I think it would move around too much and be unpredictable, like a semi flat tyre??

I ran a 225/40/18 on a 7.5J - no probs.

Title: Re: increasing the tyre width .....
Post by: Teutonic_Tamer on June 29, 2009, 05:36:35 pm
cheers guys , so the rim width and clearance are an issue  :happy2:

Im wondering whether to go to 235/40/18 as every little helps BUT Im worried about the difference re triggering my ESP as Im only changing the fronts.
Be nice to try something different though.

I have just put an axle set of 235/40 ZR18s on my standard GTI, with the standard Monza IIs.  When on the front, they actually make the speedo more accurate, on either axle, absolutely no issues with rubbing.  And you might find that 235s are easier to get hold of, as that is the most common size on virtually all modern Audis.  :happy2:

Don't forget to tweak your tyre pressures to cope with the different load indexes though.  :wink:
Title: Re: increasing the tyre width .....
Post by: Teutonic_Tamer on June 29, 2009, 06:00:13 pm
Whilst a wider tyre on a small rim may improve traction, I'd be worried about how the sidewall performed on cornering - I could see it rolling a fair bit.

The only time sidewall performance is questionable is when the sidewall is 'streched'.  Indeed, before this modern craze, the tread width was always wider than the wheel rim, rather than the other way round as is today.  Not the best of pics, but this shows that even OEMs are stretching!  All  :sick: IMVHO!
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2FTeutonic_Tamer%2Fmy_B7_RS4_saloon%2Fcea7856c.jpg&hash=6afb02363677a0ef30e9ecc6d60c4bf4e6d10066)
Title: Re: increasing the tyre width .....
Post by: Msportman on June 29, 2009, 11:44:16 pm
I'm running 235x 18 Dunlop D01J track tyres. Put them on this week on my Pescara's.
 They are ex VW Cup tyres and are superb for traction....they sit slightly fatter on rim being an 7.5j.
I used to run these on my BBS CH's on a 18x 8.5j rim and they were perfect....will review these later for these rims but initially they seem good....no clearance issues.

Ian
Title: Re: increasing the tyre width .....
Post by: Janner_Sy on July 09, 2009, 07:48:15 pm
how much difference will 235 tyres make on a 7.5 inch width alloy over the standard 225 tyre
Title: Re: increasing the tyre width .....
Post by: xxx_mojo_xxx on August 22, 2009, 12:14:38 pm
Has anyone got snaps of 235/40/18 tyres on a GTi.... like to see how they look before taking the plunge.

Also, are there any compromises that I need to be aware of?
Title: Re: increasing the tyre width .....
Post by: bacillus on August 22, 2009, 12:51:20 pm
Has anyone got snaps of 235/40/18 tyres on a GTi.... like to see how they look before taking the plunge.

Also, are there any compromises that I need to be aware of?

Why not just PM TT for some pics of his fitment?
Title: Re: increasing the tyre width .....
Post by: Top Cat on August 22, 2009, 01:44:31 pm
Guys i am ordering my R 888's on Monday for my new track wheels which are 17in by 7.5J.

Is it safe to put 235 R888's on a 7.5j wheel that is only for track days. TT is alluding above to them being put on a daily drive, my worry is the tyre wall when flying round a track.  :happy2:  :happy2:
Title: Re: increasing the tyre width .....
Post by: Janner_Sy on August 22, 2009, 01:52:29 pm
225 R888s will give you a huge improvement, iirc i read somewhere on here, it might be one of jonnyc threads, but the 225R888 has a bigger contact patch than a 225 road tyre,
Title: Re: increasing the tyre width .....
Post by: Hurdy on August 22, 2009, 03:11:45 pm
I've ordered R888's at 225/45/17's for my 17" TDPR1.2's (when they arrive)

Here's the link to their advised fittings on alloys...

http://www.toyo.co.uk/productdetail.php?identity=products&product_id=18

As you can see the 225 section on the 17" tyre already has a 231mm contact width, which is better than the 18" equivalent.

TC - with your camber adjustable top mounts you can get away with the 235 section rubber, but be aware that it is only just on the bottom end of the width fitting for the alloys at 7.5" wide. :happy2:

I thought really long and hard whether or not to get the 235's with an 8" alloy, but without the adjustability of the top mounts (like TC) they would have rubbed and I wanted to be fairly low and clear under full suspension compression. :smiley:
Title: Re: increasing the tyre width .....
Post by: Poverty on August 22, 2009, 04:05:23 pm
IIRC VW racing fit 235's to their mk5's?
Title: Re: increasing the tyre width .....
Post by: Hurdy on August 22, 2009, 04:15:47 pm
IIRC VW racing fit 235's to their mk5's?

Yes, but you can't just give an arbitary width like that without knowing everything else about the car...

Alloy diameter and width?
Suspension set up - VWR use a varied amount of set-ups including using top-mounts for extra camber adjustment
How low they go with the suspension.

These all contribute. :happy2:

Title: Re: increasing the tyre width .....
Post by: Poverty on August 22, 2009, 04:34:19 pm
IIRC VW racing fit 235's to their mk5's?

Yes, but you can't just give an arbitary width like that without knowing everything else about the car...

Alloy diameter and width?
Suspension set up - VWR use a varied amount of set-ups including using top-mounts for extra camber adjustment
How low they go with the suspension.

These all contribute. :happy2:



19 inch 8.5 width for road and track use.
Title: Re: increasing the tyre width .....
Post by: Hurdy on August 22, 2009, 04:36:21 pm

19 inch 8.5 width for road and track use.

Then they would NEED that width to get the tyre to fit, any narrower and it wouldn't be a race car it would be a stretched tyred show car :signLOL:
Title: Re: increasing the tyre width .....
Post by: RedRobin on August 22, 2009, 04:46:06 pm
....

As Hurdy says, the suspension setup has to be taken into consideration as well when changing tyre widths.
Title: Re: increasing the tyre width .....
Post by: Teutonic_Tamer on August 24, 2009, 06:04:46 pm
Guys i am ordering my R 888's on Monday for my new track wheels which are 17in by 7.5J.

Is it safe to put 235 R888's on a 7.5j wheel that is only for track days. TT is alluding above to them being put on a daily drive, my worry is the tyre wall when flying round a track.  :happy2:  :happy2:

I can't comment specifically on the R888s, but even when using the same 40 profile, changing from a 225 to a 235 is only a 10mm overall increase - so that is just 5mm per 'sidewall'.  And on my PS2s, they fill the standard Monza II rims everso slightly better - and should help if you have a propensity to park near kerbs.  Doing some calculations proves that 235/40 18s makes the GTI speedo more accurate than the standard 225s

And on the track - well if you make the same preparations as you would with the standard width tyres - then you will, or will not cross the same pit falls.  It all depends on your driving style.  :wink:
Title: Re: increasing the tyre width .....
Post by: Teutonic_Tamer on August 24, 2009, 06:06:13 pm
IIRC VW racing fit 235's to their mk5's?

Yes, but you can't just give an arbitary width like that without knowing everything else about the car...

Alloy diameter and width?
Suspension set up - VWR use a varied amount of set-ups including using top-mounts for extra camber adjustment
How low they go with the suspension.

These all contribute. :happy2:



And don't forget the rim offset too.  :happy2:
Title: Re: increasing the tyre width .....
Post by: xxx_mojo_xxx on August 24, 2009, 07:49:49 pm
"And on the track - well if you make the same preparations as you would with the standard width tyres - then you will, or will not cross the same pit falls.  It all depends on your driving style.  "

Please elaborate...
Title: Re: increasing the tyre width .....
Post by: Teutonic_Tamer on September 18, 2009, 04:25:59 pm
how much difference will 235 tyres make on a 7.5 inch width alloy over the standard 225 tyre

5mm wider for each sidewall! :wink:
Title: Re: increasing the tyre width .....
Post by: Teutonic_Tamer on September 18, 2009, 04:29:18 pm
Has anyone got snaps of 235/40/18 tyres on a GTi.... like to see how they look before taking the plunge.

Also, are there any compromises that I need to be aware of?

Just do it.  You seriously wont notice a difference, appart from a marginal increase in the safety margin for kerbing your alloys.  The standard width is 225 - which is millimetres, and 235 is just an inrease of 10 mm.
Title: Re: increasing the tyre width .....
Post by: gazbutS3 on September 18, 2009, 05:32:39 pm
the sidewall will be slightly higher too, 40% of 235mm instead of 40%of 225mm, which makes it about 4mm taller which will make your speedo read slighty under which isn't a bad thing really :laugh:
Title: Re: increasing the tyre width .....
Post by: xxx_mojo_xxx on September 18, 2009, 07:15:07 pm
Only concerns are
1) it doesn't look odd with extra rubber bulging out from the sides;
2) degrade road handling;
3) increase the risk of scrubbing inside the wheel arches (esp. on my sportlines)

May be I should go for 230s instead?

Is anyone riding on 235s on stock Monza 2s - keen to hear from them...  :party:
Title: Re: increasing the tyre width .....
Post by: Teutonic_Tamer on September 19, 2009, 02:21:01 am
Only concerns are
1) it doesn't look odd with extra rubber bulging out from the sides;
2) degrade road handling;
3) increase the risk of scrubbing inside the wheel arches (esp. on my sportlines)

May be I should go for 230s instead?

Is anyone riding on 235s on stock Monza 2s - keen to hear from them...  :party:

Yes, ME!  I got one axle set of 225, and the other axle is 235.  They don't foul on anythhing, they certainly dont degrade the handling, and they dont look odd either!
Title: Re: increasing the tyre width .....
Post by: RedRobin on September 19, 2009, 08:58:20 am

Is anyone riding on 235s on stock Monza 2s - keen to hear from them...  :party:


Yes, ME!  I got one axle set of 225, and the other axle is 235.  They don't foul on anythhing, they certainly dont degrade the handling, and they dont look odd either!


....235 on the front or rear?

Any particular reason you are riding this way?

:happy2:
Title: Re: increasing the tyre width .....
Post by: Janner_Sy on September 21, 2009, 09:06:51 am
the way of thinking is to put the tyres with the most gripon the rear of the car so that in an incident where you are about to lose control, your car will understeer as the rear outgrips the front, but thats boring, so Id put the 235 tyres on the front
Title: Re: increasing the tyre width .....
Post by: Teutonic_Tamer on October 23, 2009, 01:43:01 am

Is anyone riding on 235s on stock Monza 2s - keen to hear from them...  :party:


Yes, ME!  I got one axle set of 225, and the other axle is 235.  They don't foul on anythhing, they certainly dont degrade the handling, and they dont look odd either!


....235 on the front or rear?

Any particular reason you are riding this way?

:happy2:

I changed to 235s because I'm fed up with not having any protection to the rim.  235s give a marginal, but still worthwhile extra bit of protection to the alloys from kerb rash. :ashamed:

And by keeping the same 40 profile, the everso slightly larger rolling radius helps eliminate the inbuilt error in the speedo.  Above about 90mph (on German Autobahns  :wink:), the GTI speedo gets wildly optimistic, and these 235s help rein in some of that over-reading error.

And the reason they are on the rear - new tyres on the rear axle (but only after scrubbing them in for a couple of hundred miles on the fronts).  The 225s still on the front are nearly worn out now, and they havn't interfered with either the flat tyre warning, nor the ASR or ESP.

On my RS4, I'll be taking an even bigger step, going from the standard 255s up to 275s!  :jumpmove:
Title: Re: increasing the tyre width .....
Post by: RedRobin on October 23, 2009, 09:52:08 am

I changed to 235s because I'm fed up with not having any protection to the rim.  235s give a marginal, but still worthwhile extra bit of protection to the alloys from kerb rash. :ashamed:


....My Goodyear F1 Assymetrics have excellent rim protection - Something I've noticed since changing from Monza 18's to OZ Alleggerita 18x8's.

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fb308%2FRedRobin_05%2FRimProtector.jpg&hash=a4971a2d1800cbbacde3a5951aae47e8bc7da01c)
Title: Re: increasing the tyre width .....
Post by: Teutonic_Tamer on October 23, 2009, 05:40:17 pm

I changed to 235s because I'm fed up with not having any protection to the rim.  235s give a marginal, but still worthwhile extra bit of protection to the alloys from kerb rash. :ashamed:


....My Goodyear F1 Assymetrics have excellent rim protection - Something I've noticed since changing from Monza 18's to OZ Alleggerita 18x8's.

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fb308%2FRedRobin_05%2FRimProtector.jpg&hash=a4971a2d1800cbbacde3a5951aae47e8bc7da01c)

Thoses F1s are identical to the 'stretched' PS2s on the RS4 - but due to the stretching, they are as useful as a Dairy Milk fireguard!
Title: Re: increasing the tyre width .....
Post by: RedRobin on October 23, 2009, 05:52:05 pm

....My Goodyear F1 Assymetrics have excellent rim protection - Something I've noticed since changing from Monza 18's to OZ Alleggerita 18x8's.


Thoses F1s are identical to the 'stretched' PS2s on the RS4 - but due to the stretching, they are as useful as a Dairy Milk fireguard!


....Well, fortunately having kerbed my Monza 17's within the first fortnight of ownership (distracted by a pretty female passenger talking to me) I always need a taxi to the kerb. So I've no occasion to test the chocolate rim protector (Ooops! That sounds a bit naughty!).
Title: Re: increasing the tyre width .....
Post by: xxx_mojo_xxx on October 23, 2009, 11:26:27 pm
TT you got any snaps of your tyres on the rims to compare and contrast?
Title: Re: increasing the tyre width .....
Post by: RedRobin on November 06, 2009, 12:48:18 pm
....

So, it seems I could change my Goodyear F1 Assyms from 225 to 235 on my 18x8 OZ Alleggerita's. I better read this thread to see if any arch rubbing would be expected.
Title: Re: increasing the tyre width .....
Post by: xxx_mojo_xxx on November 10, 2009, 08:02:47 pm
I'm close to a change of front tyres... I'll be looking to change all four to Michelin Pilot Sport 2s... but I don't want to be the guinea pig with the 235s...

Title: Re: increasing the tyre width .....
Post by: xxx_mojo_xxx on November 10, 2009, 08:19:11 pm
And the point of the photo is?
Title: Re: increasing the tyre width .....
Post by: RedRobin on November 10, 2009, 08:45:29 pm

And the point of the photo is?


....What can happen to Guinea Pigs. End up as a meal on a plate.

Sorry if it offends I'll remove.
Title: Re: increasing the tyre width .....
Post by: danishmkvgti on November 10, 2009, 08:55:31 pm

And the point of the photo is?


....What can happen to Guinea Pigs. End up as a meal on a plate.

Sorry if it offends I'll remove.

thank you
Title: Re: increasing the tyre width .....
Post by: xxx_mojo_xxx on November 10, 2009, 08:57:32 pm

And the point of the photo is?


....What can happen to Guinea Pigs. End up as a meal on a plate.

Sorry if it offends I'll remove.
No offence taken, mate... it was actually funny...even though I couldn't work out  the joke.  :drinking:
Title: Re: increasing the tyre width .....
Post by: RedRobin on November 10, 2009, 10:01:59 pm

And the point of the photo is?


....What can happen to Guinea Pigs. End up as a meal on a plate.

Sorry if it offends I'll remove.

thank you


....Removed  :smiley:
Title: Re: increasing the tyre width .....
Post by: xxx_mojo_xxx on November 10, 2009, 10:09:00 pm
OK, now I'm confused...who and why would the photo be considered offensive? Sorry - I realise it's a little off-topic...
Title: Re: increasing the tyre width .....
Post by: danishmkvgti on November 11, 2009, 06:29:45 am
Thank you RR, and to answer your question Mojo: a fried rat are in my eyes distasteful and in my eyes, moreof it's a bad example for a guinea pig, this one i believe is more in line with what RR feel he would like to avoid:

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fi715.photobucket.com%2Falbums%2Fww160%2Fjakethemoss%2Fguineapigs.jpg&hash=5c138cbe07cd38c45e240ba9ddc7e2cccadb1e18)
Title: Re: increasing the tyre width .....
Post by: RedRobin on November 11, 2009, 08:59:08 am

I'm close to a change of front tyres... I'll be looking to change all four to Michelin Pilot Sport 2s... but I don't want to be the guinea pig with the 235s...


....I don't think you'd be the first and therefore 'the guinea pig'.

I recently spoke to Goodyear Technical about changing my Assymetrics from 225 to 235 next time around but we concluded that doing so would throw up other issues such as my suspension setup and also arch rubbing and even the increased possibility of aquaplaning. We decided that if it works (which mine does) don't mend it.

But other guys have done it and report no problems.
Title: Re: increasing the tyre width .....
Post by: animal on November 11, 2009, 09:53:10 am
My father used to test tyres for the police, and has a lot of experience in the matter - including finding out what happens when you maintain 100mph+ on a run-flat that has already blown... But thats a different story.

Although not on a Golf, I changed from Continental 215/40/17 to Goodyear 225/40/17 on my current car and it made a world of difference. The Conti's were not worn, I just hated them, they were noisey and didn't grip that well.

Wider, low profile tyres will always be more prone to aqua planing, another few mm is going to make a negligible difference. All this talk of tyre wall flex due to more rubber on the rim is not an issue if you adjsut your pressure accordingly as TT eluded too. Especially for track use. And the extra tyre wall is just more rubber when cornering hard...  :wink:
Title: Re: increasing the tyre width .....
Post by: xxx_mojo_xxx on November 11, 2009, 11:18:27 am
This is great...so just to nail this on the head...  Going to 235s doesn't cause rubbing issues in the arches, etc. ?
Title: Re: increasing the tyre width .....
Post by: tony_danza on November 11, 2009, 12:32:59 pm
Having just changed from a 225/40/18 F1 assym to a 225/40/18 PS2 - one thing I have noticed is the latter is ever so slightly narrower at the shoulder, making it less inclined to rub.

However, seeing a 225 & 235 PS2 next to each other, it looked like more than 10mm to me. Something Jonny noticed before on R888s too, something like a 225 having a footprint more like 240?

Are the sizings just a rough guide??

BTW Animal - I think the sidewall deflection points was talking in extremes of stretch and oversizing.
Title: Re: increasing the tyre width .....
Post by: RedRobin on November 11, 2009, 12:39:58 pm

This is great...so just to nail this on the head...  Going to 235s doesn't cause rubbing issues in the arches, etc. ?


....It depends how tight your clearances are to start with. Practical (just!) but quite tight in my case. Also the degree of movement (stiffness etc) in your suspension.
Title: Re: increasing the tyre width .....
Post by: animal on November 11, 2009, 03:47:30 pm

This is great...so just to nail this on the head...  Going to 235s doesn't cause rubbing issues in the arches, etc. ?


....It depends how tight your clearances are to start with. Practical (just!) but quite tight in my case. Also the degree of movement (stiffness etc) in your suspension.

And, it would seem in some cases, the brand of tyre too.