Sumitomo tire abberation?

I just put new Sumitomo HTZ III's on my '03 C4 (18" wheels) They are much quieter than the almost worn out Bridgestone's that were replaced. However, while the Bridgestones were unidirectional, the Sumi's are not. Each tire has an "outside" cast as part of the sidewall. So, in fact, they could be rotated from side to side on the car (which I am not planning on doing).

I suppose that you could, but I do not think that you would gain much in terms of longevity of the tyre though.

I'm on my 3rd set of Sumi's and always found them to be quite loud. Get barely 10k on rears 3 times that up front.

The Pirelli P Zero Rosso and Continental Extreme are also inside/outside and not directional. Are you sure the Sumi's used to be?

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I stopped buying them after one set for that reason, and a few others.

You get what you pay for. No rear is going to last on a well-driven 996 more than about 12-15K anyway. I went to Sumis about 1,000 miles back from a set of Conti DWs that I hated. The DWs never felt planted. The Sumis are much better so far. That said, Sumis flat-spot like crazy. First few miles in colder temps are bumpy. They also have a more rounded shoulder than many other Max Performance Summer tires, and so even at 285 they look a bit smaller in the rear. Again, you get what you pay for. For less than $700 bought, shipped, mounted, and balanced, I'm happy.

The Sumi's are a great value and perform as well as some tires at double the price. They do flat spot when sitting overnight, but clear up in a mile or 2 They are great tires for a DD Decent performance for AX and track. If you want to be competitive in AX or track, they are not the right tire

After reading the various reviews and talking to Tire Rack, I bought a set of HTR Ziii for use at an HPDE. Long story short, one of the rears has chunks coming of the center tread blocks, after a single DE in cool conditions on a standard 997. As I'd specifically asked TR about chunking, and was assured that the Sumitomos were suitable for this use, Tire Rack now tell me that they have no responsibility, but did tell me I could use the tires, just monitor closely for possible failure! They may be ok for street use, but if you use them hard, I wouldn't recommend these tires. I'm very disappointed with the performance of the tires and the advice received from Tire Rack.

The Z3s will chunk at HPDE. You can drive around it, either by taking a cool lap mid-session, getting stuck behind slower cars, or altering your driving style but it's going to happen. Doesn't mean the tires won't work, just annoying to see. I've even chunked mine at autox after a half-dozen hot-laps. They are excellent for the money, I had the same flat-spotting experience mentioned earlier, and the sidewalls are stiff compared to some competitors. Unless you run a ton of circle-track, shouldn't need to rotate l/r. The indy500s are a similar-budget tire with excellent performance, and one of the locals ran a set at tons of events without any chunking after 2 track days and tons of autox on a heavier more powerful car at a faster pace than me. Softer sidewalls too, if you're into that.

Rymerc Looks like you know things that Tire Rack don't!

I used my HTR ZIII's at a DE once.....just to see what they would do. While they aren't great track tires (but great street tires) I didn't experience any chunking whatsoever. And these were with tires that were mostly full tread. If someone experienced chunking I suspect they were running incorrect tire pressures and built too much heat.

This is what happened to my Left side Sumitomos after a hot track day in August. Until then I was having a lot of fun with them. They were low on grip and made a lot of noise but fun nonetheless. Lots of opportunity to focus on car control. I have since moved on to Nittos but would certainly use the Sumitomos as a rain tire and a tire to get to and from the track. Interestingly they don't develop enough grip to roll over on the shoulder so you could probably reduce negative camber a bit with them to make them last a bit longer on the street.

Very happy with my Sumitomo HTZ III I purchased in April of this year. I am not using them on the track but for every day driving they seem very quiet to me.

outside just means the tread pattern needs to be to the inside of the car and outside of the car to match its design, thats not directional, directional is when it has arrows showing the rotating direction. all tires are going to start getting noisy after about 5000 mi

Curious on updates as I just ordered a set for the rear. I needed cheap tires fast...PO had Federals on the rear and I hate how loud they are.

I have them on my 2002 (they were on it when I bought it). They seem to have a very good price, and they're okay tires. I experience them flat spotting when cold, taking a couple of miles to warm up and stop being noisy. They have decent traction, but not great. There are definitely tradeoffs to go along with the price tag. I'm looking for something with a little better dry grip and some wet traction, so I am going with Michelin PS2 (on GT3 rims).

These tires are a great value. I have them mounted on my Cargraphic 3 piece wheels. 18x9.5 and 18x11. 295s on the rear. They do get flat spots after a day or two. They run right out in a few miles. My biggest surprise was the wet traction at HPDEs. These tires work well for my DD and occasional Track/Autocross days. I had Conti DW, I did not like them.

On my 2nd set. Excellent tires. They will chunk on warmer track days, or if you like as much slip angle as I do and you get em nice and hot. Grip goes to almost nothing when they're nice and worn out just before they cord - so you can have lots of fun drifting and sliding and such until they cord. Driven the fun way 10k out of rears maybe 20k out of fronts is normal - depending on camber

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I have Sumi's from a previous owner, I haven't found them to be loud or to flat spot at all. Our 996 often goes a week or so without being driven, sometimes longer, never felt any flat spotting. I always keep them at 36 PSI. Mine are 17", which are probably quieter by default than larger size wheels (which is why I always prefer the smallest wheel size available for non-tracked cars). Is your comment above because they are loud or because they wear out too fast? Can I ask what tires you are using instead that you found preferable?

I have them. So far about 2K miles on them. Love them but then again I'm not racing.

My car had a new set when I bought it . They weren't good . imo the best use for them is as I found them , a cheap set you put on if you're going to sell the car soon .

They'll work for now until the crappy Uniroyal's up front wear out. Then I can match all four with good tires

Timing is everything... I just got a flat on one of my rear Sumitomos, corded it on the inside edge of the tread. The outside of the tire looks fine, just the inner edge that wore through. The GT3 alignment is aggressive, but I didn't plan on it being that destructive. Luckily I was close to home and I have a trailer, so it was minimal drama and no cost. Time to order those PS2s.

My garage here in Upstate New York is not heated, when I had discussed different types of Summer Max Performance Street tires, one of the concerns was the long periods of sub zero temperatures that could affect certain tire compounds. Was that true?

I like the Sumitomos. I just replaced the rears at 10K miles. I have a bit of camber in the rear and they wore on the inner edge. Yes, they are thumpy when cold and have been sitting, but it works itself out in a few miles. I would rather have a fresh set of inexpensive Sumitomos every 10K miles than run a 6 year old set of Michelins that might last longer. BTW, my Sumitomos did get a little noisy towards the end of their life but fine until then.

My 04 C2 Cab had Sumi's from the PO. I had to replace one when i bought the car, the RR inside was down to the cord but the rest of the tire looked ok, and the alignment looked ok - $180 mounted and balanced. So price is very good. The three that are still on the car now have about 18k miles, the new one has 5k miles. They look like they will last a little longer (front tread depth 6, old rear at 7, new rear at 9). They don't seem quite as grippy as the PS2's i've used on my 968 but so far no issues. Not noticed flat spotting or excessive noise. Overall mileage and handling seems pretty good for the price point. I will probably not replace them with another set though. I drive pretty aggressively on the many twisties around here and want better grip - car isn't a real DD, but more for fun driving. Mileage isnt as important as smileage

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Are you going to change the alignment back to stock?

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Nope, the GT3 alignment on x74 suspension and GT3 control arms is sublime. It is totally worth wearing out tires for. It handles like a dream.

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Yup, totally agree with this. Tires don't last very long but you can thread the eye of a needle with the car.

I hope this isn't hijacking the thread, but how do you guys get the tires, what shop do you use? I've been going to Discount Tire for many years to get tires put on a Porsche, but I don't always trust them to take proper care of the wheels. I usually have them jack the car manually in the parking lot rather than driving them on the lifts in the garages. What are the alternatives? Do you order from Tire Rack and ship them to your Indy (for example)? How can I know which local tire shop will take the best care of the wheels, let alone do proper balancing, etc. Thanks!

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I get mine from TR. There is a small 4 bay family owned shop here locally that has been known for the best wheel alignments for decades, not really a Porsche shop at all. There shop suffered damage in a big flood back in 2011. They got all new state of the art, mounting, balancing and aligning equipment. They can do any size wheels, they are a favorite of the local sportscar clubs. And very reasonable. When I purchased my suspension kit, I asked mfg for alignment specs, and they aligned my car accordingly. I have them check the balance every spring on my tires and alignment every other year.