2014 S4 Mismatched Tire Question......Need advice!

[Psyten]

I am hoping to get some feedback on an issue I came across today. Approximately 2 years ago I got 4 brand new Continental Extreme DSW Tuned for the 19inch Audi rims I have. I have put around 10k on them and have been very happy.

Recently, I developed a slit in the front left tire which was replaced today under the road hazard warranty. However, they replaced the tire with a different one (apparently new model) Continental DSW06 with a different treat design which the mechanic admitted after I noticed the different looking tire. They sent me on my way claiming they can't find the original tire and it has been discontinued since I bought them. Incidentally they also sent me home withdamage on the rim (small chip and scratches), which the manager reluctantly agreed to examine next week. They assured me that having one mismatched tire is fine for the car because the tread is good enough on the other three. I am a little lost as to what to do. Leave it be and have one mismatched tire on the car? Push them to replace, at least 2 matched ones, or all four? Bite the bullet and buy three more new ones to match them up?

I have a feeling the Quattro should probably have matched tires, but it's dissappoiting to buy three more brand new tires that are in great condition. I just don't want to be cheap and then develop some mechanical issue later on, but don't want to be needlessly wasteful just to have 4 matching tires (although I know I will feel better having 4 tires look the same).

It's a little unnerving with the winter coming up here in the northeast, especially after the tire shop and the dealer said, if you have slippage or traction issue then come back. I don't want to wait 4months and end up in a ditch to come back to the either.

Any advice is much appreciated! This forum helped me get the squealing brakes issue resolved with the dealer and I know the great folks on here will give me some good advice/guidance.

[MagillaGorilla]

I have 06's on my fronts and the old DWS on my backs because I was in a similar situation. Mechanically you should be fine as long as the tread depths are fairly close. If you want you could buy 1 more and throw it on the same axle as the other 06.

[JoshDub]

Push for all four. You don't want mismatched tires from a safety or a mechanical standpoint.

[adk_audi]

Sport diff?

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[Psyten]

Sport diff?

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You know good question.....I don't think it does. However, when I was buying the car the dealer insisted it was standard for 2014 (bought new in feb 2014). I was in the modest of a bad legal issue after getting hit by a drunk driver and getting out of a car that should have been totaled but Audi took it in trade and had a good deal on the table, that I didn't haggle much over the sport diff at the time. So bottom line, still not entirely sure if it does......I had a moment of weakness this summer and almost traded it for a new s5 convertible and the dealer insisted my model didn't have it standard.......never made the deal but still do t know if it does or doesn't. I assume it doesn't since I can't find it on the window sticker.....


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[14S4GWM]

^ It is not standard and its easy to tell just by looking at the diff.

[draekin13]

I would go for all 4, at minimum 2. My car was in an accident (still waiting to get my car back) and it states in about 5 spots in the owners manual that you need to replace all 4 at same time, they state traction control and ABS possibly not working correctly if they are not all the same.

[Acejam]

Push for all 4, but don't settle for less than 2. The important thing here is matching tread depth so the differentials don't get whacked. Tread pattern is important too, but you're substantially better off having at least a matching set on the same axle.


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[DeViLz x DeMoN]

I would say all 4 would be the best idea. As having 2 different and especially 3 different could cause issues with the differentials in the future. Basically different tread depths means different rolling diameters make for a constant difference of speed between left and right, as well as front and rear. The diffs will always be working which could lead to them wearing out. It could also depend on what tread depths your new tire has vs the other 3. You also have to consider weather the different brands and treads of tires could react differently to different road conditions causing an unstable car. Just my 2 cents! Good luck :)

[Psyten]

^ It is not standard and its easy to tell just by looking at the diff.

Thanks for the photo.....I assume thats in the rear, I will try and take a look when I get a chance.

[Psyten]

Thanks for the feedback folks, its insightful and does confirm what I felt would be the right approach. They claimed it would make no difference since the other three tires aren't substantially worn out, but I doubt I trust them on this (or willing to take a risk). I initially tried to push for all four tires, but they balked saying the other three didn't have a road hazard issue to be covered ( I am thinking of driving through a construction zone many times over to make them a road hazard issue, lol). I inquired with Audi and they said at least two to match would be good, but weren't entirely confident. I understand that if I develop an issue later on, it will be my responsibility for repairs (which I hope to avoid).

I will push for replacement of all four because I also agree with you folks that would be the best approach, but I have a feeling they will refuse to do that and I will ned up having to buy a set of three more tires, and be left with 3 DWS with under 10K on them which I won't have a need for.

[TexasDfwS4]

Try the classified and see if you can fine one or more for cheep. Used of course

[Zapps]

A few extra bits of information for you:

I don't own an S4 but an A4 and had the same situation. The DWS Tuned & DWS 06 aren't that different. It's not like comparing the 06 to a completely different tire.

I got "Wheel Diameter Improbable" CEL for about 2 months and it finally went away after storing tire pressures during a routine pressure check. The CEL occurred after about 5 miles of driving once tire pressure was stored.

The tire shop checked tread depth and each was within 1/32" of the new tire, I watched the tech measure each. Audi recommended all 4 tires be within 4/32".

Continental explained their diameter tolerance was something surprisingly large, much larger than the 4/32" tread depth required by Audi.

Because a CEL was generated, the ABS system is sensitive enough to detect the difference. It was probably not a good idea to only replace just the one.

I never bothered to measure tire circumference (roll over a string / tire tape) to see if the issue was the slightly different tread pattern, or the actual diameter. Being that the CEL went away, I'm assuming that the tread pattern is not the issue but the actual diameter.

I can't imagine our or any car is equipped with sensors to measure rolling resistance. The ABS determines tire "pressure" by number of rotations, I believe. A much simpler and crude measurement.

With this information, I concluded that the new tire was larger in diameter due to tolerance, wore down due to normal driving, and probably put additional stress on the differential.

With this in mind, if you don't get a CEL, I wouldn't worry about it. If you do, compare tread depth. If depths are very close, get the shop to find you a tire on the low side of the tolerance. Or go for 2 new tires on the same axle / all 4.

You will find a buyer for your old 1 or 3. I put a gouge in the 06 sidewall and could be one of them!

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[Psyten]

A few extra bits of information for you:

I don't own an S4 but an A4 and had the same situation. The DWS Tuned & DWS 06 aren't that different. It's not like comparing the 06 to a completely different tire.

I got "Wheel Diameter Improbable" CEL for about 2 months and it finally went away after storing tire pressures during a routine pressure check. The CEL occurred after about 5 miles of driving once tire pressure was stored.

The tire shop checked tread depth and each was within 1/32" of the new tire, I watched the tech measure each. Audi recommended all 4 tires be within 4/32".

Continental explained their diameter tolerance was something surprisingly large, much larger than the 4/32" tread depth required by Audi.

Because a CEL was generated, the ABS system is sensitive enough to detect the difference. It was probably not a good idea to only replace just the one.

I never bothered to measure tire circumference (roll over a string / tire tape) to see if the issue was the slightly different tread pattern, or the actual diameter. Being that the CEL went away, I'm assuming that the tread pattern is not the issue but the actual diameter.

I can't imagine our or any car is equipped with sensors to measure rolling resistance. The ABS determines tire "pressure" by number of rotations, I believe. A much simpler and crude measurement.

With this information, I concluded that the new tire was larger in diameter due to tolerance, wore down due to normal driving, and probably put additional stress on the differential.

With this in mind, if you don't get a CEL, I wouldn't worry about it. If you do, compare tread depth. If depths are very close, get the shop to find you a tire on the low side of the tolerance. Or go for 2 new tires on the same axle / all 4.

You will find a buyer for your old 1 or 3. I put a gouge in the 06 sidewall and could be one of them!

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Hey Zapps......I actually just read your previous issue on another forum from February about this issue. The problem you describe is exactly what I am concerned about. I had the dealer test drive the car today and confirm it pulls to the left now, whereas before it tracked dead straight no matter what road whatsoever. I am thinking it's the differing tire on the front left......he did give me the information exactly like you and a few others have said, anything greater than 4/32 difference is not recommended. Nevertheless, he said the problems with differentials from unmatched sizes is a real issue but didn't think I'd have a problem. I am still uneasy about this, especially since he didn't really measure the tread depth and nobody accepting responsibility down the road if issues develop. I will go back to the true place on Monday and see what they are willing to do, at least fix the rim damage I expect.....but I have a feeling I will end up having to buy three dsw06s and look to sell the dsw's (which still have 8/32 tread left with one having 7/32). Hopefully I can find a seller for these if that's the route I go......


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[superswiss]

It's stated in the user manual that all 4 tires should be same brand, size, tread pattern and similar wear. As stated above Audi states a tolerance of 4/32". The issue with not having the same tires even with the same brand and size is that not all tires have the same circumference. Different tire designs even if the size is the same have varying diameters and all the sudden you are outside of the 4/32" tolerance in diameter that quattro allows. Road hazard insurance won't cover this unfortunately. You'll have to cough up and buy 3 new matching tires. Different tires also have different grip characteristics that can confuse ESP. Over on AW an S5 owner was recently in a similar situation. His tire shop replaced two tires with a different brand. His ESP started to go off for no reason and then he replaced the other two tires and all was good afterwards. You may be ok, the new tire may be close enough to your old ones, but differentials are expensive if you have to replace them down the road. Much more expensive, then 3 new tires.

[Zapps]

I'm going to assume that because Continental used different molds between these generations, the generations ended up with different diameters.

It makes zero sense that Audi requires 4/32" max deviation across 4, yet Continental's tolerance is 3% (found my notes from a call with Continental). 3% of 26" nominal tires = 0.78" > Audi's 0.125" (4/32"). If each tire from a particular mold run had that much deviation, a set of new "identical" tires could cause this issue. This issue would be much more widespread.

The recommendation for 4 matched tires comes from the assumption that in a particular mold's lifetime, the deviation in diameter must be less that 4/32". Not as much to do with the actual tread per se, but the diameter from a particular mold. New tread = new mold.

While I threw caution to the wind, it would be prudent to replace at least one tire if you plan to keep your car for a while.

Another option (cheaper) would be to find a shop that does tire shaving and get the new one trimmed down to 8/32"

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Edit: If you do decide you buy new tires & sell the old, PM me, I'm in Philly.

[DeViLz x DeMoN]

With the 0.78 of an inch + or - could mean a difference between 2 new tires of over an inch and a half. Which to me seems a bit high. The 0.125 (3mm) seems like a fairly reasonable figure for tire differences. As new tires usually have a depth of around 0.35 inches (8-9mm).

[Psyten]

Your comment actually forced me to loo through the owner's manual in greater detail and you are entirely correct! I found all of the spots where it strongly recommends the same tire, pattern, etc. I have decided that the safest option may be to just match up the other three tires and keep all of them identical and consistent. Checking on ordering them with the Audi dealer currently.

Definitely agree that replacing three tires is much cheaper than the potential of a differential replacement/repair and/or risking any handling or traction issue, especially as the winter season comes in.

As for the tire shop that replaced the tire, they seemed to be at a loss for definitive explanation on which route to take. In the end, they did agree to fix the damage they caused on the rim, hoping this will happen this week. Needless to say, i won't be buying tires from them anymore. Better stick with the Audi dealer who price matches and has taken good care of the car over the past few years.

Hope to say this is case closed and I will work on figuring out what to do with the other good three tires.....

It's stated in the user manual that all 4 tires should be same brand, size, tread pattern and similar wear. As stated above Audi states a tolerance of 4/32". The issue with not having the same tires even with the same brand and size is that not all tires have the same circumference. Different tire designs even if the size is the same have varying diameters and all the sudden you are outside of the 4/32" tolerance in diameter that quattro allows. Road hazard insurance won't cover this unfortunately. You'll have to cough up and buy 3 new matching tires. Different tires also have different grip characteristics that can confuse ESP. Over on AW an S5 owner was recently in a similar situation. His tire shop replaced two tires with a different brand. His ESP started to go off for no reason and then he replaced the other two tires and all was good afterwards. You may be ok, the new tire may be close enough to your old ones, but differentials are expensive if you have to replace them down the road. Much more expensive, then 3 new tires.