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Discussion Starter #1
Hi,
I just have a question regarding tire mixing and matching. On my audi a5 3.2 quattro i got a tear on my back right tire and a bump on my front right (ran over a rock that was placed on the left lane..:no:). So i thought i'd bring my back left tire to the front (so both front tires are OEM tires) and buy new Hankook tires for the back with the same diameter (255/35ZR19) models....what do you think? should i go with Dunlop for all or just change the back 2 seeing that the cost is around $350 cheaper to get Hankook rather than Dunlop...

What do you guys think? I should take a decision within a week so any comments would be HIGHLY appreciated!
 

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You should ALWAYS change all four times at the same time. They will wear the same, they will affect your handling/stability/dynamics the same, etc.

In a 2-wheel-drive car, you can SOMETIMES get away with only changing fronts/rears. Even then, this is not a good idea and should only be done when there is no other option.

For a 4WD or AWD like your Audi Quattro, you MUST change all four tires at the same time, and you you must use all four identical tires. The short answer to "why?" is that you are over-taxing the differential because of the different friction rates on each wheel. Even when wheels wear non-uniformly (e.g. for whatever reason fronts have 50% tread left and rears are at 20%) you MUST change all four tires simultaneously on an AWD car.

Sure, it's an inconvenience, but so is using premium gas. And so is buying an Audi instead of a Honda. Treat it right :).
 

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well, I agree to most of the explanation :)
the idea is, that both tires and the front wheels should have about the same thread-wear as both tires on the rear wheels.

but on most modern quatro's the rear tires wear more than the front ones.
that's why front and rear tires are often interchanged, half way their life time.

this does not mean you must not have different makes of tires on the front or the rear. it means they should have about the same perimeter.
if not, you will cause extra wear to the torsen-diff.
 

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I agree with that in theory, Fred. However, you have to be careful with "same perimeter". What Fred means is that even the difference of 40% wear or 60% wear the tires will have slightly different circumferences. In fact, I think that could even be true of just different brands/tires, even when they are the same size. That is why I will always feel better changing all four at the same time.

In any case, Messi, the answer is this: you MUST NOT use 2 brand new tires and 2 part-worn tires for any reason on your car, no matter where you put them.
 

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If You're Not Going Racing ...

First things first. An Audi Quatro is a lot different than the typical all-wheel-drive or four-wheel drive. Different topic but Audis are significantly different.

One tire will always slip and/or travel a different distance than the other three. If they didn't, you would never get around a corner.

Tires are rated for speed and wear. Match your new tires to the stock tires not only on the size but also the speed rating. You may have to only get "close" with the wear rating. Your tire dealer should be able to do that or, you can research it on the Internet.

As for the rears then having a different amount of wear than the fronts, they have that now. Fronts always wear different than rears , that's why we rotate our tires.

So unless you're going racing, you should have no problem.
 

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Discussion Starter #6
Thanks fred, ebudaj and daytona! your comments gave me a huge sigh or relief...though would i matter if i said i only have 9800km (6,800 miles) on the ride from the day i took it out of the dealer?

You do have a point that changing all the tires is better for the car's handling, computing and what not, but seeing that the hankook is much well talked about (w ww.tirerack.com/survey/SurveyComments.jsp?additionalComments=Y&commentStatus=P&tireMake=Hankook&tireModel=Ventus+V12+evo+K110) thats the reason why i ask if i could mix and match, though they seem to be very similar to the dunlop...What tires do you guys have and did you hear of any similar story before?
 

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Messi -- it's not like your car is going to explode, just like it wouldn't explode if you used 89 octane or if you rode the clutch a little too much or if you didn't do your break-in correctly or..... etc. etc.

My point was simply this -- it is correct and much better for your car to (1) use the same tires on all four wheels and (2) replace all four tires at the same time.

If $500 is going to mean the world to you, then by all means put on two new tires, leave two, and rotate them frequently to keep them wearing evenly. But the "real" answer to your question is replace all four tires at the same time with four identical tires.
 

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from new, my car had Conti's.
they lasted 30..000 km and were never changed from front to read and visa versa.
in the end the front tires were close to the tire-wear-indicator.
the rears had a bit more left, but not enough, in my opinion.
the new tires are Dunlop SP Sport TT.
after about 15.000 km I will see to it, that fronts and rears will be interchanged.

the size is 245/40 ZR18 - 97Y
 

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@ebudaj,

Enjoyed reading your informative posts!

FWIW, I would never mix tires on any of my cars for the same reasons stated above...
 

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Well, my A5 3.0 tdi quattro has now 130.000 kms, and always has had its front and rear tyres interchange at about 15.000 kms.
In fact, the rear tyres always wear less than the front tyres, so at last I have ended with two new tyres on the front axle and semi worn tyres on the rear axle.

It has allowed me to buy tyres 2 by 2, and right know my car has 2 good year f1 asymmetric 2 tyres on the front and two contisport 5p on the rear, being all 255-35/19 96Y XL.

My car has 130.000 kms and that Tyre combination is perfect for the car's performance...

There has never been any problems in the car with the quattro and I will keep on using this way of buying tyres because like that I can test more tyres brands and compare them on a better way...
 

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Labomba, glad to hear its working out for you. However, as you may or may not know, the Quattro system is basically the torsen differential, which is entirely mechanical. You wouldn't necessarily get an electrical warning if there were any issues or problems. I'm not saying its happening, but if there was additional wear being put on the differential you wouldn't necessarily know it until someone doing service on your car told you it needed replacing. Best of luck though!
 

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You should ALWAYS change all four times at the same time. They will wear the same, they will affect your handling/stability/dynamics the same, etc.

In a 2-wheel-drive car, you can SOMETIMES get away with only changing fronts/rears. Even then, this is not a good idea and should only be done when there is no other option.

For a 4WD or AWD like your Audi Quattro, you MUST change all four tires at the same time, and you you must use all four identical tires. The short answer to "why?" is that you are over-taxing the differential because of the different friction rates on each wheel. Even when wheels wear non-uniformly (e.g. for whatever reason fronts have 50% tread left and rears are at 20%) you MUST change all four tires simultaneously on an AWD car.

Sure, it's an inconvenience, but so is using premium gas. And so is buying an Audi instead of a Honda. Treat it right :).
Sorry dude you are talking shit, you do not need to change all 4 tyres at the same time on a Audi quattro at the same time. For starters the quattro is predominantly driven by the front, don't quote me but the ratio is something like 60/40 front/back

Also the front will also always wear quicker than the rears because a. That's where the majority of the weight is from the engine, and b. The weight is distributed from cornering, breaking and roundabouts !
 

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Howdy:

First of all, the B8 platform employs a 3rd-generation torsen differential that utilizes a 40-60 power split, biased toward the rear axle. That is why your A5 feels sportier than some other AWD cars.

Secondly, you are correct that the tires will wear differently, however this is what makes it even MORE important that you change all 4 tires at the same time. Having tires with different levels of wear WILL result in undue stress being put on your center differential.

RTFM.
 

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Don't waste your money on Conti's-they could be one of the more expensive tires and maybe the worst for wear, I prefer Vredsetein best all around summer and if you go with the wintrac for winter you will be just as happy and they won't empty your wallet!
 

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so we haven't come to a conclusion, is it better to change all the tires at the same time or it doesn't matter on this 3rd generation quattro with sport diff?
 

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The proper answer is, unless you have 2 tires with very little wear, you must change all four tires at the same time. Furthermore, you should use the same exact model of tire on all four wheels.

The good-enough, probably-won't-do-any-too-serious-damage answer is just change the fronts and rears each as sets of 2 and buy whatever you want.

I suppose only you can decide if you want to treat your Audi properly or just "good enough".
 

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In theory, edubaj is correct. It's better to change all four tires on an AWD car. Here's a good explanation of why that is the case:

Car Talk: Shortcut on tires will end up being very costly - seattlepi.com

In reality, you should be fine unless you are trying to match two brand new tires with two well worn ones (and even then you'd probably be fine...the Torsen differential is quite sturdy). I mean, you are not going to replace all four tires if you get a flat, right?

Since your tires have less 10,000 km on them, I think you'll be okay. Put the new tires on the front wheels and keep the worn ones on the back.
 

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hmm, my Dad used to own a V70 R AWD Volvo , and Volvo had a serious problem with the centre diff tolerance, particularly on the v70 AWD models. The tolerance of the diff between the rolling radius of the front and rear tyres was only 2mm!!!!! A friend of mine works for VOlvo and he told me of countless cases of customers wrecking diffs because of ignorance or ill-advice.

HOWEVER......

I have had 2 audis, both quattros, and my dad has had 4, all quattros, and I looked into this quite deeply before he bought the first, given the problems, or expense he had encountered with the Volvo which required a new set of tyres every 9K or so, and 4 0f them because of the diff tolerance or lack therof!! (It ate tyres!)

After talking with as many different people, technicians, gearbox specialists, I actually even asked 2 dealer technicians to be sure, becuase of the problems experienced in the past, the general opinion was that the Quattro diff set up was pretty toletrant of differences in tyre wear.

I appreciate common sense has to prevail, and that fitting 17s to the front and 19s to the rear is no going to do the diff any favours, but a few mm in tread depth wear, (in my opinion) between front and rear, based on what i found out is not going to have any effect at all. My old S4 did 96K using Pirelli PZero's changing 2 tyres at a time, and I didn't have a problem. I really feel that that wasnt 'just lucky'! Stick to the same tyre brand all round, and so long as you do not have illegal tyres on one axle and brand new on the other I am pretty sure you will be absolutely fine!
 

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If you're using the car just for typical commuting and not performance driving, I would concur with what MonzaA5 said. Put the new tires on the front and keep the worn ones on the back. In practice, it'll be just fine.
 

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Discussion Starter #20
ebud, Vorsprung_DT, awesome zaragoza member, gentlemen....i thank you all for your reply's for even after changing the tires i was still reading your posts as to whether i made the right decesion or not.

Comparison between All Dunlop Tires Sport Maxx GT vs. 2 Dunlop Sport Maxx GT (back) and 2 Hankook Venus V12 (back)

Problem: A bad day on the road, where a huge rock was in the middle of the highway, caught my right tires and burst the back tire and a small bump on the front (sadly had to change that aswell, but as the 2-pair rule for changing tires...got lucky).

Solution: Thanks to all of you and heavy research online for the best tires that people saw a massive change to the original Dunlop tires fitted on the Audi A5 and A4, Hankook Venus was the best, i also was checking the datasheet and it turns out its the best for hot weather (Such as the weather in Bahrain). The dimensions and model is exactly the same so i made sure (from the owner's manual) that i wasnt even pushing my luck with the diameter, radius, thread, etc....So i changed the tires and all was well.

Problem's Encountered: i saw that the steering wheel when positioned in the middle, the car would steer to the right. Did the necessary wheel alignment and it still persisted...the guy told me the camber might have been affected....that just shut me down! Went to the agent and he told me that "Most of the problems that occur is due to tire pressure or the air inside being not equal to the pressure that should be" he took a bit of air from the new tires and poof it seems to be working fine (even though my mind is still set on the steering wheel not being in the middle).

Testing: Did a good test on the traction control and it seems pretty well! Loving the Hankook tires because i actually feel less of the road bumps and small white caps on the road, so well done Hankook! Also, maybe because the difference in miles is barely 7,000 miles between the new and old tires, they seem to be coping well. Therefore, nothing seems to have changed as per the stability of the car, driving comfort (bit better), no understeer seen or oversteer (atleast for now).

Will take the car for a drive at midnight on the weekend and will let you guys know.

If anyone wants any more clarifications on what i mentioned please dont hesitate to ask :)

Thanks again guys!
 
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