Sumitomo HTRZ5 -- Don't Do It!
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03-02-2020 | 07:21 PM
#17
RL Community Team
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From: Prunedale, CA
I was just shopping for tires to replace my Sumi III's and I was looking at the Z5's. I found several threads of people claiming they felt like a step backwards from the III's. I was not a big fan of any of the Sumi's I have had in the past do I went with the GMax's instead. So far I'm very impressed with them.
03-02-2020 | 10:38 PM
#19
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8th Gear
Joined: Nov 2010
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From: Scottsdale, AZ
Hi Leftlane -- The Sumitomos were on my car for 650 miles and got up to normal temp at least 25 times. Does that qualify as "broken in"? They were as wild on mile 650 as they were on mile one. Also, the mismatched PS4S front/P Zero rear worked perfectly right out of the box. I still say that the Sumitomos need to be approached with caution! The Generals sound like a much better budget option.
Looking back at my old 2001 non-TT 996, multiple sets of Michelin PS2's on the front were paired with the following rears: Hankook Ventus V12 (twice), Bridgestone Potenza Re050 Pole Position, Falken Azenis, Pirelli P-Zero Asimetrico, Continental Extremecontact DW (twice) and the matching Michelin PS2. The Falkens were the only ones that were not great, but they were completely predictable and stable, unlike the Sumitomos on the TT. For optimal driving on the Autobahn or track, I agree that mis-matching tires is an unnecessary risk. For daily driving, all of the other brands worked fine (and most of those were also tracked relatively safely!).
Looking back at my old 2001 non-TT 996, multiple sets of Michelin PS2's on the front were paired with the following rears: Hankook Ventus V12 (twice), Bridgestone Potenza Re050 Pole Position, Falken Azenis, Pirelli P-Zero Asimetrico, Continental Extremecontact DW (twice) and the matching Michelin PS2. The Falkens were the only ones that were not great, but they were completely predictable and stable, unlike the Sumitomos on the TT. For optimal driving on the Autobahn or track, I agree that mis-matching tires is an unnecessary risk. For daily driving, all of the other brands worked fine (and most of those were also tracked relatively safely!).
03-03-2020 | 09:24 AM
#20
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From: kansas
After consulting with various Porsche and Tire forums and yielding to my frugal nature, I replaced the threadbare rear Pirelli P Zeros on my 2004 996 Turbo X50 Cab with Sumitomo HTRZ5's. While I didn't see any threads regarding the HTRZ5's on 996TTs specifically, there seemed to be a general consensus that the predecessor HTRZ III's were a reasonable budget option on 996's. I believed these posts and assumed (danger!) that the updated tire model would be even better. What a mistake!
With the new tires, the rear immediately felt loose during lane changes and mild cornering. More spirited cornering resulted in the feeling of the rear end swinging out -- like the rear suspension was broken or the tire sidewalls were folding over on themselves. My first suspicion was that the tires were dramatically under-inflated. The pressures were at about 38lbs cold, so I inflated to 44lbs cold as dictated by the manual. The hip-swinging behavior was unimpressed by appropriate air pressure.
After several hundred miles I finally found an opportunity drive around a bend at considerable speed, and before achieving remotely interesting G's, the "nannies" kicked in, engaging the front ABS, forcing the car to straighten out. It felt very unsafe.
So I returned to Discount Tire, where a very professional service guy negotiated a full refund from their supplier (Tire Rack!). For a mere $50 per tire we upgraded to the Pirelli P Zero, and all is well in Porscheland again. Live and learn.
Additional information.... This is our 5th Porsche, and we've run hundreds of thousands of incident-free miles on non N-rated tires, many of which were on non-premium brands such as Hankook and Dunlop. Given my druthers, I'd always run Michelin PS4s's (as are on the front of this car and on all corners of our other car), but they are not available in 295/30/18, and the PS2's seemed crazy expensive for non-matching tires that only last about 12K miles. I don't track this car, so the Pirellis seemed/seem fine.
With the new tires, the rear immediately felt loose during lane changes and mild cornering. More spirited cornering resulted in the feeling of the rear end swinging out -- like the rear suspension was broken or the tire sidewalls were folding over on themselves. My first suspicion was that the tires were dramatically under-inflated. The pressures were at about 38lbs cold, so I inflated to 44lbs cold as dictated by the manual. The hip-swinging behavior was unimpressed by appropriate air pressure.
After several hundred miles I finally found an opportunity drive around a bend at considerable speed, and before achieving remotely interesting G's, the "nannies" kicked in, engaging the front ABS, forcing the car to straighten out. It felt very unsafe.
So I returned to Discount Tire, where a very professional service guy negotiated a full refund from their supplier (Tire Rack!). For a mere $50 per tire we upgraded to the Pirelli P Zero, and all is well in Porscheland again. Live and learn.
Additional information.... This is our 5th Porsche, and we've run hundreds of thousands of incident-free miles on non N-rated tires, many of which were on non-premium brands such as Hankook and Dunlop. Given my druthers, I'd always run Michelin PS4s's (as are on the front of this car and on all corners of our other car), but they are not available in 295/30/18, and the PS2's seemed crazy expensive for non-matching tires that only last about 12K miles. I don't track this car, so the Pirellis seemed/seem fine.
03-03-2020 | 05:04 PM
#22
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From: kansas
I see.
I have Sumitomo III's on my 993 C4S. I have Michelin PSS's on my M5. The Michelin's are stickier and have a stiffer sidewall. I've had both vehicles on the track. When matched properly both sets (Michelin and Sumitomo) performed as I expected. The Michelin's definitely perform better, but the Sumitomo's are predictable.
My guess is that you had a higher performing, stickier tire on the front and one with less capability on the rear. I personally never mix manufacturers, tires with different sidewall stiffness, or tread patterns. Chances are even the composition was different. Just a choice I've made to always match front and rears; may be overkill.
I will say I'm on my 3rd set of Sumitomo's so they are perfectly fine the way I drive my 993. I've never tried the next generation but would have no problem trying them as long as the front's and rear's are matched and they are going on my 993. I probably would not put the Sumitomo's on my TTS; primarily because of the power the TT can put down. The traction control light flashes frequently with the Continental all seasons I use during cold weather. My guess is the Sumitomo's, even the summer tires, would do the same.
Anyway, glad you got it straight.
I have Sumitomo III's on my 993 C4S. I have Michelin PSS's on my M5. The Michelin's are stickier and have a stiffer sidewall. I've had both vehicles on the track. When matched properly both sets (Michelin and Sumitomo) performed as I expected. The Michelin's definitely perform better, but the Sumitomo's are predictable.
My guess is that you had a higher performing, stickier tire on the front and one with less capability on the rear. I personally never mix manufacturers, tires with different sidewall stiffness, or tread patterns. Chances are even the composition was different. Just a choice I've made to always match front and rears; may be overkill.
I will say I'm on my 3rd set of Sumitomo's so they are perfectly fine the way I drive my 993. I've never tried the next generation but would have no problem trying them as long as the front's and rear's are matched and they are going on my 993. I probably would not put the Sumitomo's on my TTS; primarily because of the power the TT can put down. The traction control light flashes frequently with the Continental all seasons I use during cold weather. My guess is the Sumitomo's, even the summer tires, would do the same.
Anyway, glad you got it straight.
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FRUNKenstein (03-08-2020)
03-08-2020 | 12:38 PM
#24
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Joined: Jun 2003
Posts: 6,015
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From: Overland Park, KS
Good info, thanks for posting. Looks like it goes til April 30th. I need a set - just want a new set of the Flow One Race Spec F2 wheels in 8.5” fronts and 11” rears to go with them!
03-10-2020 | 12:40 AM
#25
Racer
Joined: Sep 2019
Posts: 402
Likes: 81
From: Maryland
After consulting with various Porsche and Tire forums and yielding to my frugal nature, I replaced the threadbare rear Pirelli P Zeros on my 2004 996 Turbo X50 Cab with Sumitomo HTRZ5's. While I didn't see any threads regarding the HTRZ5's on 996TTs specifically, there seemed to be a general consensus that the predecessor HTRZ III's were a reasonable budget option on 996's. I believed these posts and assumed (danger!) that the updated tire model would be even better. What a mistake!
With the new tires, the rear immediately felt loose during lane changes and mild cornering. More spirited cornering resulted in the feeling of the rear end swinging out -- like the rear suspension was broken or the tire sidewalls were folding over on themselves. My first suspicion was that the tires were dramatically under-inflated. The pressures were at about 38lbs cold, so I inflated to 44lbs cold as dictated by the manual. The hip-swinging behavior was unimpressed by appropriate air pressure.
After several hundred miles I finally found an opportunity drive around a bend at considerable speed, and before achieving remotely interesting G's, the "nannies" kicked in, engaging the front ABS, forcing the car to straighten out. It felt very unsafe.
So I returned to Discount Tire, where a very professional service guy negotiated a full refund from their supplier (Tire Rack!). For a mere $50 per tire we upgraded to the Pirelli P Zero, and all is well in Porscheland again. Live and learn.
Additional information.... This is our 5th Porsche, and we've run hundreds of thousands of incident-free miles on non N-rated tires, many of which were on non-premium brands such as Hankook and Dunlop. Given my druthers, I'd always run Michelin PS4s's (as are on the front of this car and on all corners of our other car), but they are not available in 295/30/18, and the PS2's seemed crazy expensive for non-matching tires that only last about 12K miles. I don't track this car, so the Pirellis seemed/seem fine.
With the new tires, the rear immediately felt loose during lane changes and mild cornering. More spirited cornering resulted in the feeling of the rear end swinging out -- like the rear suspension was broken or the tire sidewalls were folding over on themselves. My first suspicion was that the tires were dramatically under-inflated. The pressures were at about 38lbs cold, so I inflated to 44lbs cold as dictated by the manual. The hip-swinging behavior was unimpressed by appropriate air pressure.
After several hundred miles I finally found an opportunity drive around a bend at considerable speed, and before achieving remotely interesting G's, the "nannies" kicked in, engaging the front ABS, forcing the car to straighten out. It felt very unsafe.
So I returned to Discount Tire, where a very professional service guy negotiated a full refund from their supplier (Tire Rack!). For a mere $50 per tire we upgraded to the Pirelli P Zero, and all is well in Porscheland again. Live and learn.
Additional information.... This is our 5th Porsche, and we've run hundreds of thousands of incident-free miles on non N-rated tires, many of which were on non-premium brands such as Hankook and Dunlop. Given my druthers, I'd always run Michelin PS4s's (as are on the front of this car and on all corners of our other car), but they are not available in 295/30/18, and the PS2's seemed crazy expensive for non-matching tires that only last about 12K miles. I don't track this car, so the Pirellis seemed/seem fine.
03-10-2020 | 11:22 AM
#26
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From: kansas
Please provide an update once you’ve had a chance to push it in warmer weather. I would like to know how a matched set of this new generation performs.
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FRUNKenstein (03-10-2020)
03-10-2020 | 04:04 PM
#27
Three Wheelin'
Joined: Apr 2011
Posts: 1,327
Likes: 181
From: TX
I would t do the Generals.
they are fine if you drive to dinner or Home Depot but beyond that...they are also very good on wet.
the sidewall is too soft
in stock sizes, they augment understeer
I’m not going to talk about the de lamination of my General Tires that occurred on track, yet I’ve never experienced this with any other brands (kumho, Hankook etc).
i’d rather do the Pirelli PZERO at $850 than the Generals at $550
they are fine if you drive to dinner or Home Depot but beyond that...they are also very good on wet.
the sidewall is too soft
in stock sizes, they augment understeer
I’m not going to talk about the de lamination of my General Tires that occurred on track, yet I’ve never experienced this with any other brands (kumho, Hankook etc).
i’d rather do the Pirelli PZERO at $850 than the Generals at $550
03-21-2020 | 11:25 AM
#29
Track Day
Joined: May 2018
Posts: 19
Likes: 5
Just had the General G-Max RS installed yesterday on my 2004 C4S. Coming out of Sumi HTRZ-III.
First impression: A smart decision. Aside from just being happy for tread again, they feel pretty good.
Yesterday was a total mixed bag, and not fair to assess a new tire's high performance traits. Day peaked near 70 degrees (in upstate NY!) and fell to 40 degrees with 45-mph winds while driving home. Rain off and on. Given the conditions, I think the tire did great - and I definitely pushed it hard. To that end, the sidewalls do feel soft on on/off ramps.
FWIW, I have the same on my Audi A4 Avant, and felt similar soft sidewalls. Fair trade for the price.
Now curious how long they will last ...
First impression: A smart decision. Aside from just being happy for tread again, they feel pretty good.
Yesterday was a total mixed bag, and not fair to assess a new tire's high performance traits. Day peaked near 70 degrees (in upstate NY!) and fell to 40 degrees with 45-mph winds while driving home. Rain off and on. Given the conditions, I think the tire did great - and I definitely pushed it hard. To that end, the sidewalls do feel soft on on/off ramps.
FWIW, I have the same on my Audi A4 Avant, and felt similar soft sidewalls. Fair trade for the price.
Now curious how long they will last ...
03-21-2020 | 02:01 PM
#30
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Joined: Jan 2015
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From: Seattle
PSS load rating in 295/35-18 = 1,929 lb vs. 1,653 for the HTRz5
https://tbc.scene7.com/is/content/TB...%20Z5_0519.pdf
https://www.michelinman.com/tires/pi...per-sport.html
https://tbc.scene7.com/is/content/TB...%20Z5_0519.pdf
https://www.michelinman.com/tires/pi...per-sport.html