Audi Quattro and tyre matching

[blueg33]

Hi

I emailed Audi regarding the need for matched tyres on a quattro and though people would be interested in their response. (I have crossed out names for privacy)

Audi Customer Services said:

Reference: AU-2012/02-022XXX

Re: Audi A6 - VK07 XXX


Dear Mr XXXX

Thank you for your email of 23 February regarding the tread patterns on your vehicles tyres.

I have spoken with our technicians regarding this, and I have been advised that even though your vehicle does have mechanical
diffs, it does need to have the same tread patterns and manufacturer.

It is now an old ruling that the tyre treads will need to be of the same levels, the reasoning for this ruling was because of
the different rolling circumferences, but we have now updated our four wheel drive couplings so that this no longer is required.

I hope that this answers your query, but if not please contact me or one of my colleagues on the details below to discuss
further.

Kind Regards


XXX
Customer Relations Advisor
Audi UK

E [e-mail]

[Dr G]

Been asked numerous times and I'm yet to see a reason why you can't run different pairs front to rear.

I've never seen different tread depths cause a problem either.

[blueg33]

Thats why I asked them. I was looking for an explanation particularly as the diffs are mechanical rather than viscous. So they have tweaked their advice, but still not explained!

Off topic - Dr G - what is the market like for a 2007 A6 3.0tdi Le Mans Saloon with 88k miles?

[Nick1point9]

I reckon this 'rumour' about 4 identical tyres and tread depths was started by a tyre fitter trying to sell a full set and has escalated to people genuinely believing it is a requirement. You don't have to have identical tyres and tread depths across the front axle of a front wheel drive car (connected by a diff) so why would you need it front to rear on a 4WD car.

[Dr G]

3.0 Le Mans popular as long as it's a decent colour and has a few bits of spec; saloons are particularly good value right now.

[blueg33]

Dr G said:

3.0 Le Mans popular as long as it's a decent colour and has a few bits of spec; saloons are particularly good value right now.

Thanks. I probably need to sell mine. daytona, MMi high, satnav etc - hopefully attractive. 1 owner, full Audi history etc. Great car, but need to reassess the family fleet to teach son to drive. Cars are all auto and I am not teaching him in the tuscan!

[Dilligaf10]

I'll start the bidding at a tenner!

Edited due to damn iPad!

Edited by Dilligaf10 on Wednesday 7th March 15:33

[Yertis]

As far as I understand the use of four identical tyres stems from concerns that fitting tyres of different circumference and grip capabilities accelerates wear in the diffs of 'proper' quattros (by that I mean 01E gearbox and derivatives). Obviously wear will mean there is always a slight difference in tyre circumference but Audi sought to mitigate this as far as possible by specifying identical treads etc. Maybe the technology has moved on and it isn't an issue with newer systems.

But that aside, the grip and handling of quattros is compromised by fitting odd tyres, and to avoided if poss.

[blueg33]

Why would a tosrsen diff see more wear with mismatched tyres, thats the bit I don't quite get. Wheels must be rotating at different speeds a fair amount oif the time. Where I live you have to travel for a few miles before you can find a half mile long stretch of straight road. This means the diffs are working all the time with different wheel speeds

[Robatr0n]

blueg33 said:

Why would a tosrsen diff see more wear with mismatched tyres, thats the bit I don't quite get. Wheels must be rotating at different speeds a fair amount oif the time. Where I live you have to travel for a few miles before you can find a half mile long stretch of straight road. This means the diffs are working all the time with different wheel speeds

Which is precisely the reason I never bothered changing all 4 tyres at once on the S2.

I tried to make sure all 4 tyres were of the same model and brand (purely to satisfy my OCD) but in the end I was running one model of tyre on the front axle and another model of tyre on the rear.

I just made sure to replace both tyres on one axle at a time with the same make and model of tyre. I also made sure that both tyres were wearing at the same rate.

Just for reference, I clocked up 40k miles of moderate (and hard on more than the odd occassion) driving in that car and never had a problem. Depending on the type of tyre I was changing tyres every 6k-8k or 8k-10k miles. I sold it at 167k miles and the Torson diff was functioning just fine.

[legacy4cam]

I agree that the tyres matching tread patterns etc for Quattros is a little OTT, however, Audi DO stipulate this on Approved used stuff, and were good enough to cough up £250 to replace a tyre on my A8 recently, simply because it had 3 new Bridgestones and 1 new Kumho. And they let me keep the Kumho. However, I am obsessive enough to "need" matching tyres all round , I admit it , I'm OCD.

[Moog72]

I too am perhaps unreasonably OCD on tyres to the point that I replaced a perfectly servicable Conti Sport Contact 2 tyre on my old quattro A4 with a new Conti Sport 3 because that's what was on the other 3 corners when I bought it (didn't notice at the time)

[Nick1point9]

blueg33 said:

Hi

I emailed Audi regarding the need for matched tyres on a quattro and though people would be interested in their response. (I have crossed out names for privacy)

Audi Customer Services said:

Reference: AU-2012/02-022XXX

Re: Audi A6 - VK07 XXX


Dear Mr XXXX

Thank you for your email of 23 February regarding the tread patterns on your vehicles tyres.

I have spoken with our technicians regarding this, and I have been advised that even though your vehicle does have mechanical
diffs, it does need to have the same tread patterns and manufacturer.

It is now an old ruling that the tyre treads will need to be of the same levels, the reasoning for this ruling was because of
the different rolling circumferences, but we have now updated our four wheel drive couplings so that this no longer is required.

I hope that this answers your query, but if not please contact me or one of my colleagues on the details below to discuss
further.

Kind Regards


XXX
Customer Relations Advisor
Audi UK

E [e-mail]

Vehicle's

not vehicles.

I assume the letter refers to the tyres belonging to one vehicle. Honestly it's one thing making grammatical mistakes on pistonheads but in an email sent to a customer? That's poor.

[istoo]

i always bought in sets of four, but i always rotated mid wear. and true audi fashion front wore more than rears. My 21 year old quattro i found out had one different tyre for 200 laps of knockhill and the drive there and back and did give some skiterish cornering but coped. i have a relative who is ver senior with a big car insurance firm. i know he mentioned drivetrain problems with haldex car but willcheck for issues with torsen cars. like b
rand as Yertis ponted out will give different grip. st rears i found out will maske it oversteer.

[Nick1point9]

Moog72 said:

I too am perhaps unreasonably OCD on tyres to the point that I replaced a perfectly servicable Conti Sport Contact 2 tyre on my old quattro A4 with a new Conti Sport 3 because that's what was on the other 3 corners when I bought it (didn't notice at the time)

I wish I'd had more customers like you when I was running tyre garages.