lgsmith said:
In reply to Andy Hollis :
I mis-remembered; it was Britain. skip to the end for a table. The comparison to the A052 was what caught my eye (and the total time).
https://youtu.be/klSmFfLSReg?feature=shared
My hypothesis is "heavier car" but I'm not confident of that.
Based on the other tires involved, particularly the AR1 and AD09, my takeaway is that the A052 underperformed on a relative basis, rather than the AD09 overpeforming.
Here's why I think that happened...
A052 is very much a one-and-done tire at full tread depth and indeed the first lap (and only one shown, is the quickest). If you watch the A052 lap, he overdrives the tire in several spots (listen to the squall mid-corner). He also has two major wiggles, one in the slalom with the sticks, and the other at track-out. And finally, early in the lap he mentions that the car did not downshift as expected in one particular corner. Each of those is worth some time. How much? Dunno. But if I was testing and had mistakes like that, I'd redo the session.
Those two tires have such dissimilar handling characteristics, I can imagine how this happened.
Also of note, these tires were all stickers. Not heat cycled. For sure, the A052 benefits from a heat cycle. We heat cycle all of our test tires to give them a more equitable starting point.
And finally, as you mentioned, the tire-to-weight of their test was vastly different than ours...likely exacerbating the "one and done" aspect of the A052. They were running a 235/265 split on a 4000 lb car, while we were running 245 square on 2250. Huge difference. By contrast, the AD09 is super consistent, so its easy to work up to maximum pace.
Interestingly, Tire Rack put the delta at only .5 in their last track test detailed here: https://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=302 Read their commentary as to why, though. Things did not go as planned for them, either. Heck, for them the RE71RS beat the A052 by over a second. If that was true in general, nobody would be running A052's on the track for time trials. But that isn't the case.
No indivdual tire test is definitive...they are all just single data points. The best that can be hoped for is to help whittle down the choices to a manageable handful for individuals to do their own testing that matches their use case perfectly.
