The new Sumitomo HTR ZIII is the predecessor for the HTR ZII and has already received praise from TireRack, beating the Bridgestone RE050A Pole Position, Yokohama ADVAN Sport and Continental ContiSportContact 3 in their Max Performance Summer tire test. You may have seen the prices on Sumitomo tires before and thought “How good can they really be?” Well, on April 28th I took my Corvette out to Summit Point’s Shenandoah Circuit for the NERD Racing/CDC track day to find out just that.
A little information about the car. It’s 1999 Corvette 6-speed with ’08 Z06 shocks, ’04 Z06 swaybars, Carbotech AX6 pads up front and EBC Yellow’s out back. No power mods other than a modified titanium Z06 exhaust have been added. I had a fresh alignment done by PTUNING in Manassas, VA based on PFADT‘s street tire recommendations of -1.2 camber up front, -.8 out back with zero toe all around. Lastly a set of 18×9.5 SSR GT2 wheels with of course, Sumitomo HTR ZIII’s in 275/35 front and 275/40’s in the rear.
We all wish for great weather when we head out to turn some laps but on this day mother nature wasn’t so kind. It was cool, about 55 degrees, and raining steadily with puddles of standing water all around the track. Wet is the key word here. The first session out I warmed up the tires the best I could under the conditions and began to gain confidence in Sumitomo. The HTR ZIII had a very nice responsive feeling with excellent feedback. No noticeable flexing to talk about. Getting the power to the ground on a day like this was tricky, no matter what you’re driving but the HTR ZIII’s did pretty good, full throttle out of the corners in 2nd and 3rd gear was holding well. Braking was sketchy at times and constantly resulted in traction lose in the front. Maybe the tire pressure was too high, maybe it was my line, maybe it was the bite of the Carbotech’s? Whatever it was it did seem that the the front tires lost grip under moderate braking and the ABS frequently lit up the gauge cluster to say hello. In the dry I feel this tire would be much more impressive — needless to say I felt that the ZIII’s did the job just about as good as I could expect from a street tire in these wet and rainy conditions.
All that said you’d expect a bashing review. Far from it. Much of this is difficult to report because of the lack of a comparison. I’ve owned Michelin PS2’s, Bridgestone RE050A’s, RE01-R’s, 960AS’s, BFG KD’s, KDW’s, Goodyear Eagle F1 GS-D3’s, Falken RT-615’s, Hankook RS2’s and many other performance tires in the past few years and if I was to rank the Sumitomo HTR ZIII tire for the street I’d give it outstanding marks and recommend it to anyone looking for a sweet summer tire. It’s quiet, has great manners in wet and dry, very predictable, gives great driver feedback and who can argue with the price?!
This tire review is far from over — I will be back at Shenandoah Circuit on May 17-18th with TrackDaze and returning for part 2!