Mounting A New Set of skins on your late-model Corvette will put a big dent in your budget. We kept this thought in mind during a recent tire test at Spring Mountain, Nevada, where we had a chance to thrash Michelin's impressive new C6 Z06 Pilot Sport 2 Zero Pressure (PS2 ZP) tires on the racetrack. Since the Michelins carry a 10-15 percent price premium over OE Z06 replacement tires, we wanted to find out if they were worth the extra cost. To that end, we decided to put them to a real-world road test, including both low-speed city driving and an extended trip at highway velocities (and beyond). Another test on our list involved trying the new tires out on a racetrack. We spoke with Nicolas Goubert, Michelin's brand category manager, who sent us four PS2 ZPs (P275/35ZR18 front and P325/30ZR19 rear).
While we don't have a C6 Z06 in our fleet, we do have a fixed-roof coupe (FRC), in the form of our former project car, the Pewter Rocket. The Rocket is fitted with C6 Z06 reproduction wheels (9.5x18 up front and 11.0x19 in the rear) and OE tires. It weighs 3,153 pounds, while the '10 Z06 tips the scales at 3,180. The nose-heavy FRC has 51.4 percent of its weight in front and 48.6 percent in the rear. The Z06, meanwhile, boasts a near-perfect 49.3/50.7 percent distribution. The Rocket's 416ci LS2 puts out plenty of grunt, at 481 rwhp. In a previous test, its upgraded suspension (including sway bars, springs, shocks, and brakes) helped us lap Road Atlanta 1.3 seconds faster than a stock Z06. So while the cars are not identical, Editor Heath agreed they were close enough for this review.
First, we had to get our new tires mounted correctly. After our new skins arrived, we met with Ed Burge, service manager at Maher Chevrolet in St. Petersburg, Florida, to discuss our project. Maher has a full-service shop and regularly performs high-quality work on area Corvettes. Burge agreed to help us out and assigned Service Technician James Ritchey to the job.
The installation began with the FRC being placed on Maher's four-point lift so the wheels and tires could be removed. Ritchey marked each rim with tape so it could be returned to its original location; this obviates the need to recalibrate the tire-pressure sensors. The fit of the rear Z06 rims and OE tires is very tight on our C5, so we were pleasantly surprised to find that the Michelin's slightly flatter sidewall provided more clearance.
Like many high-end tire shops, Maher uses Hunter mounting, balancing, and alignment equipment. The Hunter mounting machine grasps the rim from underneath to avoid surface damage to the wheel. Ritchey applied a soap solution to each tire's bead, and the wheel was rotated as a stationary arm stretched the bead onto the rim. The tire was then inflated until it was seated securely. Because we live in a high-humidity location, Goubert recommended that we use nitrogen to fill our tires. "Regular" air retains water molecules, which can rust the bead of the rim and cause an air leak. Nitrogen does not hold moisture, eliminating this concern. After filling our tires with the specified element, Ritchey used the balance machine and stick-on weights to achieve a perfect balance. With the wheels once again bolted to the car, we were back on the road with our new skins.
The first thing we noticed was how quiet the Michelins were compared with the OE tires. The overall ride is also very comfortable. Then we took some of our favorite corners and felt a big increase in cornering grip. To verify our seat-of-the-pants impression, we called MTI Racing in Marietta, Georgia. We asked owner Reese Cox if he would track test our new tires. He agreed and invited us to a customer track day at Little Talladega Gran Prix Raceway in Munford, Alabama. The round trip was a little more than 1,400 miles, so it would be a perfect road trip for our test. We drove the Rocket 520 miles to MTI's shop in Marietta, so the car could be checked before taking it to the track. While we still experienced the classic C5/C6 rear-tire noise at speed, the Michelins were noticeably quieter than the stock rubber. But the big news was the PS2 ZPs' wet-weather performance. Despite hitting three torrential downpours on the trip, the new tires never missed a beat.
Once at MTI, the brakes were bled, the fluids checked, and track-compound brake pads installed. Our next stop was a local car show filled with more than 300 hot rods. After a fun afternoon, we headed to Little Talladega racetrack. The 10-turn, 1.40-mile road course is an excellent test of low-speed handling. After running five hot laps, Cox had this to say about the PS2 ZPs:
"Michelin makes an awesome tire. It's almost like you have a set of DOT race tires on the car. I'm amazed at the threshold of grip they provide. They also have a unique ability to regain control once you pass that threshold. Unlike the C6 Z06, this C5's front weight bias causes it to understeer more on this low-speed track layout, but it's easy to manage with these tires. I was impressed at how deep I could dive it into the braking zone and sustain very high g-forces in the corner, and how good the predictability of the PS2 ZPs was when I passed their limits. My 1:05.3 lap exceeded the 1:06.8 time that I set here in a stock C6 Z06 on OE tires. This C5 has a great combination of power and handling, and these Michelins help make it into a pretty impressive package."
In conclusion, our real-world test showed that upgrading to Michelin's new PS2 ZPs is money well spent. The tires have provided us with noticeable improvements in ride and noise quality, while also enhancing our car's track performance. Sound like a winning combination? You bet. Now it's time to clean off the Rocket's road grime and enjoy our new skins.