Bill Brewster (pcar master). 366-2009
They got the tires from their supplier.
If I lived anywhere else Tirerack would be my connection.

tw

 

ok here's the deal.

Only about a hundred miles on the tires.
Really smooth and quiet. My shop did a great balance and alignment so that's
covered. The tires are really good for overall street use once warmed up. For hard driving I'd prefer something with a stiffer sidewall. Everyone has their own opinions though. Really sticky. Just feel a little clumsy in tight situations.
They look like they'll last forever. I've heard neg on PS2's so it's all relative.
Overall: good tires

tw

 

Big day at the shop for my car:

5w-40 M1 delvac (turbo diesel) oil
75w-90 M1 delvac gear lube (not just plain M1) in the front diff and tranny
Sumitomo HTR Z III tires..


Impressions:

The balanced fine. No issues.

They look good.

Rim overhang is between the "none" of the Pirelli OEM tire and the "lots" of the Conti Contactsport 2's. There is some, but if you rely on it, your rim is toast anyway.

Did a quick 80 miles....

There is a LOT of tread release stuff on these tires and the tread is 10mm perhaps 10.5mm.... Therein lies the rub: the tires need a few miles on them before track time or really hard pushing, so I'll report back at mile 1000..and I'll measure tread. In the 80 miles, no noise (they are more quiet than pirelli, conti, and just about the same as the michelins...have had all of them..my michelins were with the car when bought with 6mm of tread though). These might be the most quiet to be honest.

Even with the above, I take a certain 120 degree right hand turn hard off the interstate every morning, so I sort of "know the turn" really well, the apex, the camber, the loading up of the car, etc. At the same speed I usally go, LESS squeal. No wiggle. Last tire was the conti and I had de'd those.... Now, I doubt all the "goop" is off the tires in 80 miles, but perhaps the treads were cleaned up. I got the tires quite warm in those 80 miles.....


No issues. I'll report back.

I suspect what TT_tommy (and I) are feeling is the shock of going from 2mm of tread to 10. I think at 6mm this tire will be nice on track. At 8mm..ok. That is why azenis are sold with 8mm of tread.....not 10.

 

Great feedback guys. Keep it coming.

 

OK. update on the tires.

REALLY good. They're not expensive and they perform well. A couple of heavy fangers this week confirm that they aren't just good tires for the price, they're good tires period.
I think that with a stiffer suspension it may not be the same conclusion though. The Sport Cups would probably prevail there.

tw

 

I will never buy PS 2's again...the biggest rip off in tires hand down. Twice as expensive as my Toyo TR 1's and only about 10% better.

Both suck on the track. I like Nitto NT01's (my "street" tire for my GT2).

How do the Sumi's compare w. T1R's? I might run them on my M3.

 

I just ran my PS Ribs on the track this weekend and I must admit, they're not PS CUP tire, but they did OK, considering the power I'm putting down.. With my new suspension settings at 2.9 front and 2.5 rear, they performed well, and were probably about 2-3 seconds off the pace of my PS Cups... These tires picked up a lot of track rubber onto them... I've never had a full street radial do that...

I'll probably give the Sumitomos a try for the street once I kill these PS Ribs, but I do not expect them to perform near the level of this tire on the track, maybe on the street... But for HALF the price, I'll try them.

Mike

 

Just put on four HTRZ III tires, 235/40's in the front, 295/30's in the rear, cost me $884.00 mounted, road force balanced and installed. I don't understand why anyone would pay more for a street tire, these things are whisper quiet compared to the Pirelli's they replaced. As far as performance, it's hard to compare a tire with zero tread to a full tread depth tire, but I can tell you the difference is minimal. If these tires are this good now, I can't wait until some of the tread is worn off. Until then the reduction in noise is worth the money alone. for the money I can go through two sets of these compared to one set of Michelins, Pirelli's or Conti's.

 

Hey Damon,

Better stock up on these!!

tw

 

Anyone tracked these yet? Need a grip comparo to the PS2's and AD07's.

 

Look at the stats on the tire before considering them for the track... They are a 300 UTQG vs. a 220 UTQG of the Michelins... I'm used to the 80 UTQG of the MPSCs, and could tell a big difference in that over the weekend...

Sumitomo appears to be a great street tire. Don't hold your breath on it being a stellar track day performer for anything above novice use.

Mike

 

Mike how does the UTQG work. The higher the number the better the wear, but less traction?

I just put a set of the Sumitomos on this weekend, and am happy with the traction and noise, so far . $750 installed, $640 from Tirerack.

 

http://www.tirerack.com/tires/tirete....jsp?techid=48

Better explanation than I can type...

But to give a better understanding:

Kumho V710s - 30 UTQG
Hoosier A6 - 40 UTQG
BFG R1 - 40 UTQG
MPSC - 80 UTQG
TOYO R888 - 100 UTQG
MPS Rib - 220 UTQG
Sumitomo HRZIII - 300 UTQG

Now the assumption is that the UTQG is a good "general" rule to go by. The higher the number, the better the tread wear on a street car, but you need to understand that when you get into tracking a car, all bets are off. For instance, the Kumho has a lower UTQG, but every T1 racer I know will run the hoosier over the Kumho if they can afford it. Yet the Kumho's number is lower.

These "affordable" street tires will be fine for guys running in novice classes. But if you plan to run 2:15s or quicker at VIR, you'll want something more sticky...

Good example is that even with the horrid track conditions at Summit Point this past weekend, I could have run a 1:22 if I were on my MPSCs. I ran a few 1:24-1:25s on my MPS-Ribs. 2-3 Seconds slower...
Mike

 

One other very important thing in regards to UTQG: Everyone thinks it's an industry number with a scale all manufacturers go by - It's NOT. It's a number that manufacturers use to rate two of THEIR tires within their respective performance categories. You cannot use those numbers to rate Michelin to Sumitomo to Dunlop, etc. Only Sumitomo to Sumitomo. And even then if you used them to rate to Sumi's together but one is an all season and the other is a sport summer they would not matter, either. Don't let them cause confusion.....

 

Right, which is explained in your online section I linked, Damon... Kinda why I commented on the Kumho vs. Hoosier comparison and how UTQGs can be misleading.

Guys, Tirerack has a WEALTH of technical info about tire/suspension/brake related stuff to educate you in your quest for knowledge of products before you buy.

Damon, based on your experience, What would you recommend for guys looking for a "cross over" do everything tire for street and road course stuff? Think in terms of Novice to intermediate HPDE candidates.

Mike