paradocs98

Quick review for anyone who is interested. I ran Yokohama AD08Rs on my 991 Carrera S last track season (255/35-19 front, 305/30-19 rear). They were also my daily duty tires. I needed a tire with good track performance and heat tolerance, as well as decent drivability on the daily commute, in the rain, etc. Pilot Super Sports were ruled out because they get hot and greasy quickly on the track.

The AD08Rs did very well. Last year I had nothing else for comparison, but they gripped well on the track and I got probably 8000 miles out of them in combined street/track driving (10 trackdays total).

This year I'm trying the new Pilot Sport Cup 2s. Treadwear rating (for what it's worth) is 180, just like that of the Yokos. But the Michelins definitely seem softer than the AD08Rs. They pick up every little pebble and bit of debris on the road. I'm more paranoid in daily driving with them. Obviously it would be ideal to have dedicated track-only tires, but I don't want to trailer the car or pull a little tire trailer behind it. So this is the best compromise for now.

I'm at NJMP Thunderbolt this weekend with NASA for the first time on the Michelins. So far so good. They are definitely grippier than the Yokohamas. Their limits seem to be significantly higher. Quieter near the limit, too. I have the Glen and VIR coming up in the next several weeks, so I'll report back with more of an assessment and info about longevity.

85Gold

Please keep us informed. It is my contention that the new High performance street tires like the AD08R, Stones RE71-R, Rival S are approaching the territory of the semi slicks like the NT01.

Peter

LexVan

I wish Yoko made the AD08Rs in our 20" sizes but I know/understand you track guys want the 19s.

Jake951

I'm definitely interested in hearing more on this comparison. I'm in the same boat in that I only run one set of wheels/tires for street and track. I'm also using the AD08R's now and find them to be the best "street" tire for the track.

paradocs98

Some followup from the weekend at NJMP. The PS Cup 2s seem to have a softer sidewall than the AD08Rs, and they also seem to demonstrate more of a pressure increase with a typical HPDE 20-25min session. There are obviously multiple factors that affect this--change in ambient temps, how hard the tires are being driven, etc., but my driving has been pretty consistent from last season (AD08Rs) to this one. I started both days this weekend around 30psi front and 33 psi rear cold, knowing that I would need to bleed off pressure as the day progressed. The first run each day brought the tires up to around 38-39 front and 41 rear, a good 2-3psi higher than the typical increase after a session on the AD08Rs. I bled them down to around 35 front and 38 rear hot, where they seemed to be happy. Traction drops off considerably when they get above 38 rear. I needed to bleed off a bit more pressure after runs 2 and 3 to keep them at 35/38, but then they stabilized.

I'd be interested to hear others' experiences with optimal track pressures for the PS Cup 2s. Wear across the tread surface looks pretty even so far (I have Sport PASM and PDCC with stock alignment settings). I'll use my pyrometer next time out to find out for sure.

zedcat

I ran my Cup 2s (991 GT3) at 32F 35R hot based on recs from the GT3 subforum and they seemed good at those pressures. I recall from the Mich UK site a recommendation for 33 to 36 hot as optimum.

Edit- I started at 26F 29R and only bled the rears 1-2 psi twice in 4 30min sessions. Track was TWS, ambient temp mid 70sF.

CosmosMpower

I ran NT01's at COTA this past weekend on Sat and RE-11 (not RE-11A) on Sunday because it rained. When it finally dried up Sunday I was able to get a somewhat comparable lap. The RE-11 are nowhere near as fast as NT01, the car pushed really bad in all the slow corners and would not turn at all on the bstones.

paradocs98

Will do. I've read the same thing--that the very latest max performance street tires are blurring the line between street and R-comp.
Yep--smallest tire/wheel that will fit over the brake calipers (or, in our case, rear lower control arms).
I liked the AD08R as well, but I suspect the PS Cup 2 is going to be a significant step up.
Good info--thanks. I'll have to see if they feel even better at these slightly lower hot pressures. Again, the pyrometer should tell here. The strange thing is I recall reading in Michelin literature that they don't recommend airing down to a low pressure to start a run, but rather starting at "normal" pressures and then bleeding air down to target hot pressures after coming back in. Not sure why they would say this, but given the 8-9 psi that the tires typically gain during that first run, it would put them well into the 40s front and rear, and it would be a slippery disaster. I don't like the idea of basically having to throw away the first run of the day because my tires are overinflated and sliding. On the other hand, it's pretty remarkable how the soft sidewall of these tires shows changes in pressures--when I started the fronts down at 30 psi cold, they looked pretty billowy and bulging. Made me nervous that any lower and they'd separate from the wheels at the bead. A distinct contrast to the AD08Rs, whose stiff sidewalls almost seem runflat-like.
I ran NT01s for a couple of years on my 2011 M3 before changing to the new Toyo RR (similar to Hoosier R6). I had forgotten how much of a step up the NT01s and especially the RRs were compared to something like the Pilot Super Sport until I ran my street Pilot Super Sports on the M3 during a mixed weather day at Pocono's infield course. The PSS, a very decent street tire, was an understeering mess. The weather cleared in the afternoon and I put the Toyo RRs back on--what an utter transformation.

JP66

I realize this is an older thread, and I know the Doc has a busy schedule and may not respond for a while, but I was wondering what pressures he ran on the AD08 Rs?

I had Simon Kirkby take my Cayman R out for a few laps at Lime Rock. Dan Jacobs from Hairy Dog Garage told me to shoot for 31-32 psi hot on the Yokohama AD08 Rs so I started at 28 psi. After only 4 laps Simon's time fell off by more than a second, and he said the tires were the problem. We pulled into the pits and found 38 psi all around. He bled the tires down to 31 and we went back out and the time dropped by almost 2 seconds.

My point here is I wonder if folks that have been trying the Yokohama's aren't perhaps running them too high. I'm no pro, but in my limited experience I would say the Yokohama's feel really "greasy" at 36 psi and the feel like they would stick forever at 32 psi.

Anyways, just wondering if other folks have had a chance to drive both these tires. I'm planning on buying a new set of tires on Monday, and I had planned on buying another set of Yoko's.

Logically isn't it true the SC2s are not R tires so they shouldn't have anywhere near the same grip?

Another wondering newbie question

changster123

I ran new AD08R's in my last 2 track sessions. Previously it was all Cup 2's. For sure the AD08R's gripped much better at under 33psi. No buts or if's about it. At above 35/36 the grip is reduced noticeably. This is on my 997.2 Turbo S.

For Cup 2's, pressure of under 35psi was good.

I feel the AD08R is almost as fast as the Cup 2's but with significantly more life. I won't go back to a Cup 2 unless I'm trying to set a street tire lap time with my peers. Cup 2's after 2 track days (my sessions are 25 minutes, 6-7 sessions a day, i.e 10-12 laps in a ~2min lap) feel like they are done. The AD08R's still have tons of tread left after my sessions last weekend.

paradocs98

I had forgotten about this thread. Good questions. I ran something like 35/38 front/rear hot pressures on the AD08Rs. In retrospect, this may have been too high. Good data points you're providing with respect to Kirkby laps and tire pressures. I wonder, though, if a direct comparison can be made, given that your Cayman and my former 991 have very different weight distributions. I now have a GT4. Going by the factory recommendations for cold tire pressures, the GT4 is supposed to run several psi lower both front and rear, with less of a differential between front and rear compared to the 991. Obviously these aren't the actual pressures you would use on track, but it's interesting that Porsche's recommendation is for the 981 chassis to run significantly lower tire pressures compared to the 991 chassis. So perhaps ideal track pressures are not just tire model/compound specific, but also car specific. On the GT4 forum, most users with track experience are running the PSCup2s at something like 32/33 front/rear hot pressures.

As for the R-comp question, the 'R' in the AD08R doesn't mean it's actually an R-comp tire. The AD08R is classified as an "extreme performance" tire by TireRack, which is the class between "max performance" and "streetable track and competition." A close-to R-comp tire would fall into the "streetable track and competition" category--examples are Yokohama's A048 and actually the Pilot Sport Cup and Cup2. A true R-comp is something like a Toyo RR or Hoosier R6/7 that you would absolutely not run on the street. So the Pilot Sport Cup2 is actually classified as a stickier, more "R-comp light" tire compared to the AD08R.

Good info. What are the exact lap time differences for you between the two different tires?

paradocs98

I had forgotten about this thread. Good questions. I ran something like 35/38 front/rear hot pressures on the AD08Rs. In retrospect, this may have been too high. Good data points you're providing with respect to Kirkby laps and tire pressures. I wonder, though, if a direct comparison can be made, given that your Cayman and my former 991 have very different weight distributions. I now have a GT4. Going by the factory recommendations for cold tire pressures, the GT4 is supposed to run several psi lower both front and rear, with less of a differential between front and rear compared to the 991. Obviously these aren't the actual pressures you would use on track, but it's interesting that Porsche's recommendation is for the 981 chassis to run significantly lower tire pressures compared to the 991 chassis. So perhaps ideal track pressures are not just tire model/compound specific, but also car specific. On the GT4 forum, most users with track experience are running the PSCup2s at something like 32/33 front/rear hot pressures.

As for the R-comp question, the 'R' in the AD08R doesn't mean it's actually an R-comp tire. The AD08R is classified as an "extreme performance" tire by TireRack, which is the class between "max performance" and "streetable track and competition." A close-to R-comp tire would fall into the "streetable track and competition" category--examples are Yokohama's A048 and actually the Pilot Sport Cup and Cup2. A true R-comp is something like a Toyo RR or Hoosier R6/7 that you would absolutely not run on the street. So the Pilot Sport Cup2 is actually classified as a stickier, more "R-comp light" tire compared to the AD08R.

Good info. What are the exact lap time differences for you between the two different tire?

zedcat

Agree with you on about 32 psi for AD08R on a Cayman R based on my experience. I have run them higher and saw accelerated wear in the center and even blistered the center. I've had Cup 2s on another car so not a direct comparison but I think they have more grip and less life than the Yokos.

changster123

2 seconds or so in a ~2min lap but it is not comparable because 1) the conditions are way different and 2) I can't say I'm an awesome driver where I can really extract everything out of both tires. But I know Cup 2's grip more. Not night and day difference but it's there. For me the longevity of the AD08R is way worth the trade off.

User 52121

Just stumbled on this thread... agree I love the Yoko's... but I've been aiming for 36psi when hot.

Sounds like maybe I'll try running them lower next time, maybe I'll try 32...