Do you rotate tires?

[SaqLocke]

I have a 2017 A4 Quattro. I bought it with 40k miles and now has 55k after a year and a half of my ownership. This morning I decided to rotate tires. On the passenger side I could not tell a difference in wear levels between front and back. On the driver side the front was slightly more worn. This is just me eyeballing it, I don’t have a tread gauge.

So it got me thinking, do you guys rotate tires or have you seen uniform wear on this platform? I know it’s always a good idea, but just curious to hear from someone with more observed miles than me.

[AccordingToAlex]

Yes, you should always rotate tires, especially on Quattro cars. Each corner will wear differently so you want to keep the wear even across all 4 tires. If there's a difference in tread depth that's greater than 4/32" , you'll fry the Quattro.

[scsu]

Yes, I used to do it every 5k miles. But now I only go about 10k a year, so I rotate when I change to the winters and vice versa.

Sent from my SM-G981V using Audizine Forum mobile app

[Manny_Fresh]

if you want your tire mileage warranty to stay good then yes. usually it's somewhere around 5k miles

[Thumper3]

Yes, you should always rotate tires, especially on Quattro cars. Each corner will wear differently so you want to keep the wear even across all 4 tires. If there's a difference in tread depth that's greater than 4/32" , you'll fry the Quattro.

100% right there.

What's hilarious is most dealers say there's no need to rotate on the Quattro LMAO

Standard would be every 10k but if you drive it hard and really carve corners better to move that up to every 5k and really keep the wear even. Plus, the real important reason is to put eyes on the tire. Track uneven wear, heck I once caught a sidewall bubble on the INNER sidewall at a rotation.

[Spawne32]

I'll wait for the explanation as to how its going to "fry the quattro".

[AccordingToAlex]

I'll wait for the explanation as to how its going to "fry the quattro".

When tread depths differ too much, it essentially makes your wheels different sizes. This puts your center differential into a frenzy, as it tries to compensate for the different rotational speeds, even in a straight line. This constant correction overheats the diff and boom, diff goes bye-bye.

[Spawne32]

When tread depths differ too much, it essentially makes your wheels different sizes. This puts your center differential into a frenzy, as it tries to compensate for the different rotational speeds, even in a straight line. This constant correction overheats the diff and boom, diff goes bye-bye.

You do understand that the center differential was designed to constantly be in motion to correct for sublte variations in traction on all wheels, correct? If your statement was correct, people who drive these cars in almost constant winter conditions, especially in other countries would smoke their center differentials in a matter of no time as no particular wheel in their weather conditions would ever have the same level of traction.

[AccordingToAlex]

You do understand that the center differential was designed to constantly be in motion to correct for sublte variations in traction on all wheels, correct? If your statement was correct, people who drive these cars in almost constant winter conditions, especially in other countries would smoke their center differentials in a matter of no time as no particular wheel in their weather conditions would ever have the same level of traction.

I suggest doing more research on how differentials work. To each their own though ¯\_(ツ)_/¯

[Spawne32]

I suggest doing more research on how differentials work. To each their own though ¯\_(ツ)_/¯

lol I know how differentials work. Audi is not so stupid as to design a system that cannot tolerate differences in tire tread depth. Trust me on that. People abuse the quattro system far worse than tire wear and you'd be amazed at how strong it is.

[Smac770]

Audi has always quoted to not exceed a front axle average tread depth vs rear axle average tread depth difference of 2mm for longitudinal (Torsen) or 3mm for transverse (Haldex). For Torsen, this represents roughly a 0.6% difference limit

I'm sure the Torsen center diff being in a constant state of lock will do it no favors. A post from a quick google search: https://www.motorgeek.com/threads/di...0/#post-555733 Though that example is more extreme, with somewhere around 1% front vs rear output shaft speed difference.

Basically, the Torsen can accommodate differing output shaft rpms, but it tries to fight that, that's the purpose. If the differing speeds are significant and forced full time, the internal gears longevity is trashed. I do wonder how the revised PAT variant compares to the planetary gear variant for output difference tolerance, if they differ at all.

Differing individual wheels speeds is the job of the open diffs on the axles, and the ESP system utilizing the brakes. I do wonder too if too much wheel speed difference would be flagged by the ESP system as "something is wrong" and cause it to fight to try and stabilize the wheel speeds at a common value, which would likely just wear out the brakes.

[Smac770]

As to the OP question, of course. Tires should always be rotated front<>rear at least on some cycle. My current tires are directional, so I get no left<>right balancing. You can't do real inner<>outer balancing without dismounting and remounting the tires. At least not till we get 0 offset reversable wheels. :-) Actually, I wonder if you could do that with 3-piece wheels, if any are designed to allow mounting to the rim from either side.

I do rotations every ~6k. As my tires normally last 22-25k, that means it's running towards the end of having tires on front and back twice. While I don't get the substantial center wear on the rear axle like my old G35, the extra shoulder wear on the front axle is as obvious as any other car.

[Spawne32]

Audi has always quoted to not exceed a front axle average tread depth vs rear axle average tread depth difference of 2mm for longitudinal (Torsen) or 3mm for transverse (Haldex). For Torsen, this represents roughly a 0.6% difference limit

I'm sure the Torsen center diff being in a constant state of lock will do it no favors. A post from a quick google search: https://www.motorgeek.com/threads/di...0/#post-555733 Though that example is more extreme, with somewhere around 1% front vs rear output shaft speed difference.

Basically, the Torsen can accommodate differing output shaft rpms, but it tries to fight that, that's the purpose. If the differing speeds are significant and forced full time, the internal gears longevity is trashed. I do wonder how the revised PAT variant compares to the planetary gear variant for output difference tolerance, if they differ at all.

Differing individual wheels speeds is the job of the open diffs on the axles, and the ESP system utilizing the brakes. I do wonder too if too much wheel speed difference would be flagged by the ESP system as "something is wrong" and cause it to fight to try and stabilize the wheel speeds at a common value, which would likely just wear out the brakes.

Torsen on the center diff was done away with after 09 was it not?

[Smac770]

No, Torsen is still the center diff even today, except for transverse VW clones using Haldex and quattro ultra using that Haldex clone system they made. The original 50:50 design (type A) usage ended around that time, but the PAT (type B) Gen2 and planetary (type C) asymmetric configs are alive and well.

[Spawne32]

No, Torsen is still the center diff even today, except for transverse VW clones using Haldex and quattro ultra using that Haldex clone system they made. The original 50:50 design (type A) usage ended around that time, but the PAT (type B) Gen2 and planetary (type C) asymmetric configs are alive and well.

So what ever happened to the crown wheel center differential that supposedly came on anything past 09 for the B8's?

[Smac770]

Crown diff was only ever on type 0B5 DL501-7Q transmissions, only on some early RoW Q5 and allroads, and on all RS4/RS5 automatic models. Crown diff is dead as of the end of B8.5 RS4/RS5.

[Spawne32]

Crown diff was only ever on type 0B5 DL501-7Q transmissions, only on some early RoW Q5 and allroads, and on all RS4/RS5 automatic models. Crown diff is dead as of the end of B8.5 RS4/RS5.

Interesting, if I recall there was a really big thread in the B8 forum regarding the changes to the center differential. I always thought that the torsen was discontinued after model year 09 and was the reason for the change in the driveshaft couplings on later models.

[Smac770]

Yeah, I made that 10 page PowerPoint detailing the history, in that thread where someone was sure the center diff in their B8.5 S4 was a crown diff.

[87vr6]

If there's a difference in tread depth that's greater than 4/32" , you'll fry the Quattro.

That is a false statement.

[AccordingToAlex]

That is a false statement.

Okay I'll let Audi know.