quattro tyre wear
Author
Discussion

Andy70

Original Poster:

1,463 posts

190 months

Thursday 3rd December 2015
quotequote all
Hi guys just curious is to how important it is with Audi 4WD cars to keep the tyres an even tread, I remember from the Impreza forums on here when I was a member that certain 4WD systems have to have an even tread on all 4 tyres or it can bugger up the 4WD but other cars it doesn't matter, any truth in this?? cheers, oh also while I'm here I notice when I do a so tight turn on full lock, it feels like the tyres scuff as I pull away, is this normal on these cars? tracking as far as I know is plumb dead straight so I've eliminated that possibility (2003 S4 Avant by the way)

MattS3

2,112 posts

222 months

Thursday 3rd December 2015
quotequote all
Tyres depths on the same axle was what I think is important.
Although I've always replaced my tyres as complete sets when I had my S4.

Regards the scrubbing at low speeds, perfectly normal.

Raven Flyer

1,645 posts

255 months

Friday 4th December 2015
quotequote all
When I bought my C6 quattro, it needed a new rear diff as the previous owner had fitted different tyres across the axle.

I'm guessing he had a puncture as the one odd tyre had a lot of tread, the other three did not.

He could have got a decent part worn tyre for less than the one budget tyre he had fitted.

This all worked to my favour as I negotiated a huge discount on the cost of the car because of the diff whine and got it rebuilt for a fraction of the cost of a new one. It was still perfect 60k miles later.


Andy70

Original Poster:

1,463 posts

190 months

Friday 4th December 2015
quotequote all
Ok, it seems quite important then on these,I'll have to buy a full set of tyres then, cheers guys

Cockernee

3,059 posts

191 months

Friday 4th December 2015
quotequote all
I was told 2mm max difference across an axle by Audi dealer. Bit of a bummer to replace 2 on the SQ5 as 1 was damaged and 3mm of wear from new frown.

Fortunately someone else paid...

Andy70

Original Poster:

1,463 posts

190 months

Friday 4th December 2015
quotequote all
lucky you, well I had a puncture in the shoulder of the tyre that couldn't be repaired on the back, the front tyres have done less than a thousand miles and the back were half worn, just to keep me going I put a part worn tyre on the back, I was thinking I'd need to replace all 4 so they are the same, but what i'll do is buy a pair and put them on the front and the front ones on the back as the front should wear quicker so should catch them up in no time :-), any one have any ideas as to what the scuffing is when I'm pulling away slowly on full lock?

hman

7,497 posts

225 months

Friday 4th December 2015
quotequote all
Total horsest, I have owned 5 quattros and replaced tyres as and when I needed - never a set, mainly one at a time sometimes in pairs .

no one died and it certainly never caused any tcs problems or diff explodage.

These are all Torsen quattros too

Ymmv

Andy70

Original Poster:

1,463 posts

190 months

Friday 4th December 2015
quotequote all
I was wondering, 3 mm is quite a bit if wear difference, it's the difference between a half worn pair and close to illegal pair almost? So Maybe It Doesn't matter much

KungFuPanda

4,645 posts

201 months

Saturday 5th December 2015
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I couldn't imagine that a pair of mismatched tyres could wreck a diff??

Andy70

Original Poster:

1,463 posts

190 months

Monday 7th December 2015
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KungFuPanda said:
I couldn't imagine that a pair of mismatched tyres could wreck a diff??
It surprises me too but with the old imprezas I think it was an issue, maybe it might have been because it was permanent 4wd??

hman

7,497 posts

225 months

Tuesday 8th December 2015
quotequote all
torsen diff audis ( 80,90, coupe, 100, 200, a4, a5, a6, a8 ) are permanent 4wd.


They dont care what tyre treads you have in my experience.


haldex (rear drive as required but not all the time)is on A3's

Yertis

19,738 posts

297 months

Tuesday 8th December 2015
quotequote all
The requirement to keep wear levels within reasonably similar levels is to minimise wear in the diffs, particularly across an axle. The need for identical tyre types /tread patterns is to help ensure predictable handling (quattros can handle strangely on mismatched tyres – BTDT). The stuff about always replacing all four at once is bks, IMO, the fronts will always be wearing faster than the rears, from the moment they're fitted.

Adrian E

3,367 posts

207 months

Wednesday 9th December 2015
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In my experience with a number of VAG cars, mostly quattro, if you rotate the tyres once in their life then all 4 will wear out at the same time anyway.

Audi recommend keeping to the same brand and model, as tyre construction varies and a different, but nominally 'identical' size tyre, can have a significantly different rolling radius to a new tyre matching the ones already on the car.

The advice in ElsaWin is to take average tread depths from each tyre, average across each axle, the difference between thos averages front to rear should be no more than 2mm. In theory you can replace 1 tyre with new and still be within acceptable limits for the diffs.

The only exception is where the diff has electronic control (ie ADS with quattro sport diff) in which case you should keep the tyres on that axle much more closely matched on tread. I can't recall if there's a figure for acceptable difference, but I know it was pointed out as more important than on a car without.

I needed 1 tyre on our old C5 A6 and got hold of a suitable part worn with similar tread depth to match the rest.

Ref tyre wear/scrubbing - it varies a lot by tyre construction and wheel size. I've scrubbed fronts on 17" wheels with Conti SC5 tyres in no time. The outer edge of the tread is very soft. Run 20s on both quattro Audis and have Michelin Super Sports on both - they don't scrub anything like others I've had. Also worth a proper wheel alignment check using Audi gear (my local indy has the factory stuff) as that can influence how the tyre wears a lot!

Dr G

15,990 posts

273 months

Wednesday 9th December 2015
quotequote all
hman said:
Total horsest
Correct.

It is good practice to have tyres in matched pairs with (ideally) reasonably similar tread depths to ensure predictable handling behaviour.

The diffs don't care.