Tweener 200tw tires: Kumho V730 vs. Yokohama AD09 vs. Nexen Sport R

300zxfreak said:

I think you guys should consider changing the name of the magazine to "Miata Tire Test Monthly".

But sometimes we do this...

https://grassrootsmotorsports.com/articles/how-to-find-the-ideal-wheel-and-tire-size/

And other times we do this...

https://grassrootsmotorsports.com/articles/tire-test-x-comp-hp/

And every once in awhile we do this...

https://grassrootsmotorsports.com/articles/200-treadwear-tire-test/

On a serious note, things have leveled off for awhile.  One new tire on the horizon for this summer, but beyond that...crickets.  Which is fine by me...testing in CenTex summer is brutal.

In reply to thashane :

v730 vs RE71RS were about 1 to 1.5 secs slower on my personal car in my very non-scientific testing: https://www.youtube.com/watch?v=cLY355jbVM0

I've seen euro tests where the AD 09r is a top endurance 200 tire, but in GRM testing it winds up being a second away. An odd discrepancy I'd love a comment on.

Also the question of tweeter tires really amounts to being "are they usable in the rain?" I don't know who is driving in an area that has no puddles when rain is actively falling, but I think a 730 doesn't have the siping to be a trustworthy street tire anywhere east of the Mississippi. I don't know anything about the nexen. The Yokohamas (which I have on my e46) seem ok driving through a storm. I've never tried to drive them aggressively in such conditions though.
 

Not saying there isn't a lot of readership in dry areas but I really would've found this more helpful with more data about fully wet performance. Something that integrates aqua planing resistance.

lgsmith said:

I've seen euro tests where the AD 09r is a top endurance 200 tire, but in GRM testing it winds up being a second away. An odd discrepancy I'd love a comment on.

Also the question of tweeter tires really amounts to being "are they usable in the rain?" I don't know who is driving in an area that has no puddles when rain is actively falling, but I think a 730 doesn't have the siping to be a trustworthy street tire anywhere east of the Mississippi. I don't know anything about the nexen. The Yokohamas (which I have on my e46) seem ok driving through a storm. I've never tried to drive them aggressively in such conditions though.
 

Not saying there isn't a lot of readership in dry areas but I really would've found this more helpful with more data about fully wet performance. Something that integrates aqua planing resistance.

Got a link to said European testing?  Hard to comment without seeing that.

As for wet performance, we don't have the facilities to test that on a consistent/scientific basis, but Tire Rack does.  And they've tested all of these in the wet.  Go to their web site, find the tire and click on "Test Results" for deets.  Some of these may surprise you.

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.

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.