It was the weekend before SEMA '07 and snow lay all around. We found ourselves in Las Vegas but our early arrival didn't require marathon laps around the show halls. Instead, we got a sneak preview of two new Dunlop tire lines before their official unveiling at SEMA: the Direzza Sport Z1 and the SP Sport Maxx GT. Both are geared toward the tuner market, so we were excited to have the Las Vegas Speedway at our disposal.
Direzza Sport Z1
A tire for weekend track days with daily-driving ability, the Direzza Sport Z1 is basically a streetlegal track tire that's competitively priced against most of the sticky tires out there. Its main feature is the tread pattern. Dunlop ' uses a unique simulator to predict how road conditions dictate tire behavior. Because of this, the Z1's directional tread is intended for dry conditions. It has both notched and continuous shoulder ribs with large shoulder blocks. The center rib is wide, creating a more consistent contact patch with the road. The compound and mold shape are maximized for dry weather grip and Dunlop used its JointLess Band technology to maintain performance at high speed.
After learning about the tire's benefits, we were taken to an autocross course where a handful of new Subaru WRX awaited us. One was on the Z1 tires, while the other had Bridgestone RE010-Rs. The latter have a slightly lower UTQG rating, meaning they should be softer. After thrashing both cars, we noticed the Dunlops reacted faster on the course, but both were similar in terms of overall grip. We should note that other drivers set faster times on the Bridgestones, but the differences were small.
The Dunlops are less expensive, however, and with sizes from 15-18", we recommend trying them on your own weekend warrior.
SP Sport Maxx GT
For big sports coupes and sedans, Dunlop introduced its SP Sport Maxx GT line. With only eight sizes available in 18" and 19", the asymmetrical tire was designed for vehicles such as the Gallardo, 911 and M5.
What's unique about these tires is Dunlop's Touch Technology. It uses a stiff sidewall to minimize flex during cornering, plus firm tread blocks and a lower tread profile to gain a larger contact patch. JointLess Band technology is also infused to help the ride quality. An asymmetrical and multiradius tread design distributes pressure evenly across the tire surface.
Like a group of kids begging to ride a rollercoaster, we were giddy to test the tires on BMW's 507hp M5 V10. A short road course within the oval track at Vegas Speedway didn't give us much room to reach high speed, but the M5 was still a thrill to drive. We attempted to take a few laps at full speed and realized the M5 isn't a purpose-built track car. Its excessive weight was a hindrance but for a stock sedan, it handled well enough and the Sport Maxx GT gripped the pavement well. We wouldn't have any concerns using these tires on canyon adventures.