Maximizing Chevrolet Corvette Z06/Z07 Track Pack Cornering: Here's the Secret Sauce

Most days, when the weather cooperates, you can find members of our testing team at one or another of our test facilities running all manner of vehicles through our extensive test regimen. One of the tests that we subject almost all vehicles to is skidpad cornering performance, which ascertains maximum lateral acceleration—the maximum steady state cornering gs that a vehicle can attain, an average of an entire lap while turning both left and right. Our testers do hundreds of skidpad tests each year, they're experts at it, and they virtually always match or exceed any claims provided to us by manufacturers about how hard their vehicles will corner. Which is why we were puzzled when we couldn't come close to the Corvette engineering group's max-lat claims for the Z06 with the Z07 track package, which includes the latest gummy Michelin Pilot Sport Cup 2 R ZP tires.

The Corvette engineers told us that the new Z07-equipped Z06 would hold on to the tarmac up to 1.22 g on a 300-foot-diameter skidpad like we typically use, and we had no reason to doubt their number as they are, like us, meticulous testers. But we only saw 1.16 g—a significant difference and well below the company's estimate. It was an even worse cornering number than we measured on the previous-generation front-engine C7 Z06/Z07, which hung on for 1.19 g. What's more, we'd just also run a 2023 Z06 convertible without the Z07 package on the skidpad, and its Michelin Pilot Sport 4S ZP tires had hung on up to 1.12 g, a big improvement over the base C8 Stingray's 1.03-g performance, one you can feel in your neck muscles. What was going on here?

Only after the Z07 Vette left our possession did Chevy tell us the secret sauce that unlocks its full cornering capability. For all of our performance testing, which includes skidpad runs, we adjust tire pressure according to the manufacturer's recommendations that are printed on the placard located on the door jamb or B-pillar, or in the owner's manual. If there are multiple choices, we'll use the high-speed, low-load specification. Oddly, the Z07's placard required the Cup 2s to be set at 35 psi cold, some 5 psi higher than the base Z06's tire pressure. Since the tires on the two versions of the Z06 are the same size, we wondered if something was off.

That had us digging deep into the Z06 owner's manual where we discovered a well-hidden suggestion: owners should lower the Cup 2 R's tire pressure all the way down to 24 psi for maximum cornering on the track. Huh? It took discussions with both the Corvette engineers and engineers from tire-maker Michelin to fully explain the situation.