On Monday I posted about choosing the right tire for your Porsche (any Posche). Specifically, I discussed how the new Sumitomo HTR Z III contradict the concept of having to pay (or over pay) for quality. My review was based on 1500 miles or so of ordinary and spirited street driving. Today's post is a review, compliments of John D. (Founder of Rennlist and PCA DE Instructor) of the Sumitomo HTR Z IIIs
on the track as compared to Michellin, Toyo, Dunlop and BF Goodrich Ultra High Performance street tires. I want to emphasize that this review is a comparison of high performance STREET tires to other high performance STREET tires. While the Sumitomo HTR ZIII is a great STREET tire, it would not be fair to compare it to a purpose built/designed track/racing tire.
John's Review of the Sumitomo HTR ZIII:
I run in the Instructors group (RED) - and the first session out was slow, to see what the tires would do and to break them in (they had less than 100 miles on them before I hit the track - not advised.) I think I was the perfect HWFM (Hey Wait For Me) Racing ombudsman during the break in.. OK...
Fast forward to the next day (3 sessions later).. Temps were about 60 degrees F in the afternoon. Tire pressures were set at 33/37 COLD (post track session - these were 36/41). Observations...??
For a street tire the HTR Z IIIs
outperformed my previous Michelans, Toyos, Dunlops, BFG tires. They have a stiffer sidewall than the HTR ZIIs (by a whole lot - which is why I didn't like the ZIIs on the track).
Performance of the ZIIIs are as follows (rated 1-10 compared to the tires above):
- Feedback - 8
- Traction - 8.5
- Braking - 9
- "Looseness" in the corners - 9
- Predictability - 9.5
- Ability to control - 9.5
- "Hot" laps - 8.5
I imagine I killed the life of these tires on the second day by - oh - about 5,000 miles - BUT - they are great tires to run to the limit.
For everyday use? Good. They will flat-spot over night - so it may take a mile or two to run them out. (I agree with John on this and have noticed it myself).
In wet weather/rain? Absolutely fine.. Back it down a notch - and they grip as well as any ultra-high-performance tire. Maybe better...
Sumitomo is a Great Tire for your Porsche
As you can see from John's review above, these tires perform extremely well. I don't make it a habit of plugging products on my site (I do it occasionally when something is worthwhile) but these Sumitomos are that good. Factor in the cost (or lack there of) and you would be crazy not to get a set for your Porsche next time you need new tires. I don't know how long before Sumitomo raises their prices, but based on the number of people I personally know who have purchased these tires, it may not be long.
Do you run these tires? Do you agree with my review from Monday? What about John's review above? I would love to hear your thoughts.
Thanks again to John D for allowing me to post his review here. If you have a minute don't forget to check out John's charitable organization Rennwish.
Related Posts
Choosing the Right Tires for Your Porsche
Understanding Porsche N Spec Approval
Tire Choices for a Porsche 993
I just got some Toyo T1R’s for the 944. Need new ball joints to get the car properly aligned, but I’ll be glad to give you my thoughts once I’m in good shape there.
Good review, but it’s from The John D. — Rennlist Superstar!
Andrew,
Would love a review of the Toyos. I’ve seen a lot of discussion on RL about them, but not great reviews yet. Are you going to install the ball-joints or have it done? If you do it yourself and have the time, take a few pics and document it. That would make a nice DIY post.
OK, the results look good. What about the noise level re highway driving?
Thanks
I have been running the Sumi’s for about a year and would agree with everything that is said in the review except one thing and that is my track experience with them. My first track session was at Laguna Seca where both myself and my instructor really put them to the test and they performed, in my opinion, better than the OEM Pirelli’s that came on my ’99 Boxster. My second DE event was at Infineon and the track temps were in the high 80′s to low 90′s in the afternoon and the rear Sumi’s got hot and chunked up to the point pieces of the tire were coming off into the next day. Up to that point, after a dozen or more AX’s, one other track session and 7K miles of street and highway driving they looked great. After that session the rears where shot and had to be replaced. The good news is the price for replacement doesn’t put a hole in your race fund. I drive with my top down as much as possible and they are less noisy than the Pirellis. Overall I really like the Sumi’s and am on my second set but would consider another brand of tire when it is time for replacement.
Ronald,
The key difference might be the heat. Both John D and I live in the New England and we simply don’t get many of those high heat days (especially on our planned DE days). I’m getting ready to replace the Sumi’s on my 993 and unless something changes I’ll be putting another set of the HTR Z IIIs.
Thanks for your input.