On Monday I posted about choosing the right tire for your Porsche (any Posche). Specifically, I discussed how the new Sumitomo HTR Z III Tire
Sumitomo HTR Z III Porsche Review
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 Michelins, 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. We don’t make it a habit of plugging products on our site (We do it occasionally when something is worthwhile) but these Sumitomo HTR Z IIIs
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 us 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
View Comments (12)
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.
On my 3rd set of Sumitomos on a 996 Turbo. Drive well wet and dry. Yes they flat spot, especially in winter, but it rolls out within a few miles. Some PSM issues, possibly due to softer than N-Spec sidewalls resulting in overly different effective front-rear or left-right rolling diameters. Not a worry to me as I like my car much better with PSM off. As for track suitability, they are pretty fast, but not especially robust. My fronts have always lasted but the rears have twice died at half tread. Now I do the occasional autocross and sprint race on them so they are being heavily tested but the first rears went with big 1 inch by 6 inch bubbles inside the sidewalls after a dry spin. The second set of rears chunked up with lumps of tread ripping off down to the cords, also at half wear. That was after one wet track day, one moist spring track day, and a few launches on coarse chip seal. Because I had two sets of one third worn fronts left over, I got another pair of rears, but had them shaved down a few mm (to 8.5mm the same as some N-specs) in an effort to have them last. I now run track tires on track but they have recently done a great job of handling a 3 day rally tour that included about 150 miles of closed road twisty stages with a 100 mph speed limit. No visible damage and only reasonable wear, while still hanging onto the likes of Gallardos, R8s and 560hp C63s running Super Sports and R-comps. If these last to the bottom of the tread I may buy another set and shave them down.
I recently installed my 3rd pair of HTR ZIII's on my 2002 Targa. No complaints except I find them quite loud. Treadlife on the rears is under 10k miles. But that being said they are a great deal of bang for the buck.
Good collection of anecdotal testimonials on these tires, but what about other options? Who is the author of the article? Hopefully not a Sumitomo dealer.
Sherwood,
The insights come courtesy of John Dunkle (Founder of Rennlist). Sumitomo had/has nothing to do with this story, nor are they a sponsor of this site...
HI, The above comments are all very good. I was very interested in every word , BUT will someone please RATE these tires for quiet running at average Highway speeds. My car is a 06 997 CARRERA S . A anniversary model "CLUB COUPE" It's a beautiful automobile BUT it is NOISEY.
It is tire noise and it is terrible My wife dislikes this car to the point of NOt wanting to ride in it . Can you imagine NOT liking a $120,000 car . THE SUSPENSION IS TUNED to the DEAD NUTS specification. THe same tire noise occurs with NEW as well as WORN tires ready for replacement.
Any suggestion ie TIRE PRESSURES , TIRE SOURCING ( ie manufacturer) would be greatly appreciated. Not everyone takes their new 997 to the track. I'm sorry to say but I agree with my wife on this one . I cannot even enjoy the sounds from the engine and exhaust over the tire noise
William, what tires are your currently running?
I ran new Sumitomos on my 993TT for a 4500 mile tour. The rears wore 60% by the end of the trip. The tires handle nice and the price is terrific compared to PS2S or Super Sports that I normally run. Great tires for the price.