Without a doubt, Michelin PS4S are the road tyre of choice at the moment.

 

Pirellis slurp!

1. You can, but they don't advise it. Some places can shave it the new one down to match the existing one.
2. They say you shouldn't, but with the R8's Quattro system, it might be okay temporarily if you keep your F:R ratio in tact.
3. yep
4. nope

 

I had a similar problem last year when I damaged the sidewall of the OE PZs. Only had 6000 miles on them but decided to replace all four with Michelin Cup2s.

PS4S are good all round performer and are now available with an Audi AO homologation as they come standard on the facelift with 20" wheels. I really doubt it makes much difference in performance.

I note your PZs are are the old design i.e not the latest PZ4. You'll probably find they have a squiggly L on the sidewall for Lamborghini. Never been a fan of them especially when cold.

 

stick a tread gauge in it to see how much is left. If it's like a 1-2/32 difference from new shouldn't make too much a difference. If you're close to the 2-3/32 they're close enough that I would just move on and replace them all. Around 3-4/32 wet traction wasn't the greatest. It was fun for a bit till I spun out and the car stopped about a foot from the curb. I don't know too much about the f:r ratio but I know it's pretty consisted that the rears wear out faster so I don't know why that would matter too much. As long as the fronts are similar in tread as well as both rears are similar it should be ok. I wouldn't put a new tire with one that was about to wear out on the same axle.

 

Other alternative could be to purchase a used PZ to keep you going until you are ready to replace all 4. I have one here at the house but it wouldn't be cost effective to send from Ireland !

 

Thats exactly the right advise. The Pirelli look like they have plenty tread left.
Buy a used one that has roughly the same tread left, +/- 1mm or even two is ok. A new one has 6.8mm till 7mm tread.
And its not the Pirellis fault the rear one is damaged

 

Thanks to everyone for their responses.

@Steve9 - you are correct. I took another look and there was the "L" on the sidewall.

I do not recall any potholes or objects that could have cause the strange void in the tire. One thing I was thinking was that there are several articles stating that the Pirelli's can crack if driven in temperatures below 45 degrees (F). I have driven the car in 40 degrees (F) - mainly for the scheduled oil change. The cracking is stated as cosmetic but it makes me wonder.

Regardless, it is what it is. I decided to go with the PS4S on all four.

 

The old PZs are poor in low temps and I noted cracking on the tyres when I bought my first V8 - they were the originals and would have been about 5 years old at the time. I never lost any chunks of rubber though but changing them out was the best thing I did on my V8.

You might have caused light damage at some point which could go unnoticed, then the cold temps has caused it to propagate.

 

The old PZs are poor in low temps and I noted cracking on the tyres when I bought my first V8 -

You might have caused light damage at some point which could go unnoticed, then the cold temps has caused it to propagate.

That tyre shows that suspension allignment toe in is by far too much and most likely combined with too less tyre pressure and high speed driving. These are no temp cracks, they happen 45 till 90 degrees to yours. These cracks show a damaged side wall carcasse.

Tire cracks when they are driven with too less tyre pressure especially on high speeds like 300kmh and the tyre carcasse gets damaged and the top layer gets loose. This happens due to force tyre slipage at speeds > 200kmh, exponantially increasing from 250 on. Thats the reason a Y- speedindex=300kmh tyre has only 80% of its load index above 270kmh. With wrong alignment and too much toe in the outside of the tyre gets even more load=LOI reduces even more. Well if you have 0.4bar to less pressure its only 60% LOI left, too much toe in 50% LOI left...far too less LOI for the axle weight of the R8=you overloaded the tyre=damage. When its getting too cold summer tyre rubber is not that flexible and because already loose top layer cracks or can even break off. And thats not cosmetic, it shows that the carcasse was damaged.
Premium tyre manufacturer like Pirelli, Conti and Michelin put a safety margin and rate the tyres lower in LOI as they actually can do to cover user mistakes like that but sometimes even this margin is not high enough to fully cover the misuse=overload.Without that safety margin that tyre would have been colapsed while driving high speed. Be happy it just shows cracks and that something is wrong and its not the Pirelli tyre thats wrong here.

Not the tyres fault and issue, wrong handling of the tyre by user.

Regularly driving PZ since years in outside temp ranges of -5 till +35 degrees on the limit of the tyres which is normal when you do spirited mountain pass tours plus high speed german highways. Never any cracking or probs happening. Same to my fellows which Porsche 911 GTS and Carrera 4.
Porsche is delivered worldwide mainly with Pirelli Zero(plus Cup2 as performance tyre) and only issue like that known internally...and Porsche/Pirelli took care immediatly. There was a screwed up charge of N0 tyres mostly cayman sizes that had cracking but they where exchange by Pirelli immediatly when a Porsche driver complained.

the picture above of the OP shows an absolute clear damage of the carcasse by something quite sharp or spot on puncturing. The steel carcasse broke, the upper layer broke too and a part of the rubber was cut off by the root cause of the damage.

 

I think the real problem is that you have Pirelli's still

 

I have a 2017 R8 with less than 10k on it and recently heard a slight, repetitive thump from one of the tires. Inspection confirmed the driver's side rear tire had a significant gash in it all the way down to the underlying steal belts, (see photo).

View attachment 236370

Looks to be purely cosmetic.

I'm kidding. So, I'm not a fan of the Pirelli's and have the following questions. Any feed back would be appreciated:

1. All of the tires have some tread left on them. The assumption is I cannot or should not replace the single defective tire.
2. If I want to abandon the Pirelli's then the assumption is I should replace all of the tires at this point as opposed to replacing the two rear P1's. In other words I shouldn't mix tires from different manufacturers, (e.g. Michelins on the rear and then eventually replacing the front tires to match - correct?)
3. Are the Michelin PS4S's the tire of choice these days?
4. Anyone in the Raleigh/Durham area, (North Carolina, USA), that can recommend a place to get these tires replaced?

Thank in advance for any advice!

NCPM,

You have a a lot of info coming at you - I won't try to address it all, but hopefully help with your original question. So you know the background of the person giving you a response - Our tires were one of my responsibilities as one of the four chassis design and release engineers on the '05-'06 Ford GT. I also did ride handling development on the FGT. I am sorry to see your badly damaged tire. Good time for the PS4S's.


1-2-3. Definitely replace tires in pairs (exact same tires). If there is not a lot of tire life left and big difference in age (more than 1 year) then it is time to head straight to the PS4S's. I agree completely with Dave L and others on these tires I will discuss below compared to two other tires.

The cracking - Pirellis are bit known for this with age. Too much toe will cause tire tread block feathering (and cupping if too much toe change...typically in braking). I don't see that here. We could talk about your usage, tire age, alignment and so on, but what I know is you didn't abuse the tire, especially if your alignment is within OEM spec (unless you were way under-inflated, which I also don't see signs of in tire wear). We could debate if the toe is too high, which I will be going through on mine in the next few weeks, but I promise the tire was developed for and run with those specs at Audi - low speed, high speed, serious handling, 24 hour durability, etc. Even if you were out a little the tire should not have this cracking. You may add some heat and uneven wear, but not overload or damage the tire like this shows. You can only truly overload these tires by going well above the top speed (aero load) or having an event in which tire damage is the least of your concerns.

I am going to write the following up in a detailed report and post when complete, but I have had a chance to compare the OEM PZeros (OEM sizes on 19's) on a 2011 R8 V10, the Hankook Ventus V12's at OEM sizes on my 2012 R8 V10. The short story is the PS4S's are 1-2 points better overall than the Pzero's for me and 3+ points better than the Hankook Ventus V12's.
So for me so far:
Steering - the PS4S are 1-2 point better than the PZeros for center feel, steering torque level and consistency, linearity/direct, feedback and wheel fight (steering wheel kicking back and forth with bumps in a straight line). The V12's are awful for steering and these attributes.
Ride - The PS4S's are 1-2 points better than the Pzero's for primary ride (big rounded bumps) and short choppy bumps and impacts. The impacts especially feel less harsh and more "rounded" (Damped) ont he PS4's. The V12's always just felt like I was bouncing on the tire.
Handling - at about 90% the grip level the PS4s' were only a little better for me than the Pzero's, but the communication of the limit, the predictability and feedback for me was 1-2 points better than the Pzero's. And drastically better than the V12's.

And I just had happen what others have noted...the V12's "went off" like we have in racing. Badly. I got about 500 miles of spirited driving in which they had decent grip, but were very vague, no feedback and not linear to suddenly no grip. I was aggressive on throttle in a straight line even and the V12's initially had decent grip with no traction control events. Then at 500 miles the traction control went crazy constantly. No grip. Done.

Hope this helps...I have this set of Hankook V12's with a lot of tread for sale! lol

 

@Scott-AhlmanPerformanceLLC - Thank you for the detailed information and your comparison of the PS4S's against the other brands. Valuable insight. The Pirelli's on the car are at least 2.5 years old. I bought the car used a little over 2 years ago with about 3600 miles on it. The alignment could be way off but as I am replacing all 4 tires with PS4S's and getting an alignment done I hopefully will not run into this issue again. Any recommendation on tire pressure for 20" 245/30 (front) and 305/30 (rear)? The owners manual says one thing and the door jamb sticker values, which the manual mentions should be consulted if different, seem very high, (49psi front, 41psi rear).

I see you are in the Mad City - been there quite a few times - fun town. Thanks again!

 

NCPM - You are most welcome. Glad to help. You won't run into this issue again with the PS4S's. Unfortunately, I don't have a good recommendation for your 20" tires...are they OEM? If so I would go with the placard on the door pressures.

Yes, Madtown is fun! Let me know if you are ever this way. Great twisties in the hills here. I spent a lot of time in Charlotte area as well with my work in NASCAR. Some good times on Lake Norman a few times.

 

NCPM, I had 3 of my 4 Pirelli PZeros develop cracks after only 4 years. My 2014 R8 only had 6,000 miles at the time and the car is a garage queen. Switched to PS4S and they are so much better! I have a long relationship with the tire store that sold me the Michelins and they sent the 4 Pirelli tires (that came with the car new) back to Pirelli for inspection and Pirelli gave the tire store $624 which they passed on back to me. I had been a loyal Pirelli fan since the 1990's but now have Michelins on all 3 of my cars as the last set of Pirellis on each of my cars has been disappointing. Seems like Pirelli is not the same quality tire it used to be.

To Helldriver and Scott-Ahlmann, my Audi dealer recommends 40 front and 38 rear as my car mainly sees road and highway use below 100mph. I've had psi set to 45/41 factory specs before and the front seems to be too light/bouncy to the point that I feel that traction is compromised. Is this normal?

 

Sorry never really answered your question about the higher pressures. The ride is significantly better at the lower pressures so in any real bumps the car does not feel good at the 45/41...for me even in normal mode. But sport mode through the bumps is not good for me at either pressures and is actually worse.

So I can see why you feel the front end too light and bouncy at the 45/41 and mid or below speeds if there are any real bumps.

The steering torque ("weight") feels lighter than too at higher pressures so that may also be adding to this sensation for you.
Never [/QUOTE]

 

OC R8, I understand what you are saying on the higher preasures, but don't feel the same in normal mode. In sport mode it feels like I am bouncing on the tires often. Locked up suspension.

Since the later R8s show 39/36 that is what I would run for lower pressure. I will be trying this later today or tomorrow and give you guys my feedback for what it is worth.

So your Audi dealership recommendation is close to those lower numbers but I would use the Audi R8 engineers numbers. Regardless, if you like the ride, handling and steering where you are then that is probably best.

The only thing else I will say is that the pressures Audi specifies take into account everything including significant evasive maneuvers that hopefully you never need but may.

 

Scott-AhlmanPerformance - thanks again for your feedback.

I had all 4 tires replaced today. The dealership checked the alignment and said it was dead on. So much for Helldriver's theory.

 

Glad to help...you went to PS4S's...right?