Specs & Details
Dunlop Direzza ZII
Type Extreme Performance Summer
UTQG 200 A A
- Tread compound delivers high levels of dry grip and handling while promoting uniform tire temperatures and even wear across the tread
- Features Dunlop's True Circle Profile that distributes tire deflection forces along the sidewall to provide more control by better communicating tire performance limits to the driver
- Two wide circumferential center grooves channel water through the center of the tread design while angled independent grooves help direct water to the sides of the footprint to enhance wet traction
- Internal structure includes JointLess Band (JLB) Technology that spirally winds polyamide cord over the two wide steel belts to promote strength, uniform ride quality, and high-speed capability
- Two-ply polyester sidewalls help resist lateral deflection and provide responsive handling and cornering stability
Scion FR-S on KW Clubsport coilovers and Brembo GT brakes
Test Driver David Pratte, Editor-at-Large
Test Track Toronto Motor-sports Park
Test Conditions Dry, sunny and warm (80° F)
Dunlop's Direzza Z1 Star Spec has been a stalwart of the extreme performance summer tire scene for quite a few years, a category that's become more and more important thanks to the growing popularity of street tire classes in both autocross and time attack, not to mention drifting and HPDE. With new and highly competitive options from BFGoodrich and Yokohama, the Direzza ZII is Dunlop's answer to the traction war that continues to blur the lines between street tire and race tire.
On the stock Michelin Primacy HP tires (240 tread wear) Scion equips the FR-S with, we saw maximum cornering g-forces of 1.0 to 1.1 g in each turn and a best lap time of 1 minute, 27.8 seconds. Ideally, we would have tested the Dunlops in the same size as the OE rubber (215/40R17) or a size with the same overall diameter (24.7 inches), but because the car's owner wanted to step up to 18-inch wheels, the best we could do to minimize the effects of a taller tire was to go with 255/35R18 (25-inch overall diameter).
Of course, with a much stickier compound (200 tread wear), a far more aggressive tread design with massive tread blocks on the shoulders, and internal construction designed to maximize on-track performance, we expected the Direzza ZII would more than compensate for its slightly taller diameter. Sure enough, lateral g-forces jumped to a very impressive 1.2 to 1.3 g in the corners, rivaling not only the best tires in class but also some of the DOT track/competition tires we've tested in recent years.
The traction circle graph shows just how much the Direzza ZII (red dots) expands or fills the circle and thus increases maximum cornering power compared to the OE tires (blue dots). It also shows an absolutely massive improvement in braking g's at the bottom center of the graph, where peak braking g's dipped to a max of -1.11 g on the Dunlops compared to a max of -0.79 g on the OE rubber, allowing us to really attack the braking zones with later and heavier application of the slow pedal.
As you'd expect with all that added lateral and longitudinal grip, lap times fell by more than 2 seconds to 1:25.5, and we're pretty sure with more setup time we could find another half second or more. The car did pick up some understeer because of the extra mechanical grip and much wider contact patches, so we began making adjustments to the damper settings and tire pressures (based on tire temperature data collected with a probe-type pyrometer), but we ran out of daylight before we could fully dial things in to our liking.
But based on this preliminary test, it would certainly appear that Dunlop has found a way to improve on the Z1 Star Spec, since the grip the ZII generated on our FR-S test mule not only rivals DOT track/competition tires but also provides crisp turn-in response and excellent at-the-limit feedback. About the only downside to the ZII is road noise, which is pretty significant at highway cruising speeds. So if you're looking for a quiet summer cruisin' tire, this ain't it. But if you're looking to shave some serious time off your lap times on a truly streetable summer tire, put Dunlop's new Direzza ZII on your short list.