We receive a lot of mail here at Team VETTE Command Central, and we read every piece of it. Much of that mail comes bearing questions. Some we can answer, some we have to pass the buck on. But then Paul Wolkenburg of Katy, Texas (among others) asked us "Will the '02 Z06 wheel and tire package fit the '02 Vette convertible body without modification to the inner walls?" In fact, the question of whether or not Z06 wheels will work on a '97-02 C5 coupe or convertible is one that we've been seeing regularly-regularly enough that we decided to go get some answers.
We enlisted Mike Sweeney at Corvette Wheel Specialist in Fountain Valley, California, to help with this project. CWS lined up our guinea pig-a gorgeous Magnetic Red '99 convertible-and Yokohama kicked in with a set of their super-sticky AVS Sport radials in Z06 sizes. We also ordered up a foursome of their new AVS Sport runflats, which come in stock C5 sizes (245/45ZR17 front, 275/40ZR18 rear), to mount on aftermarket Z06-style and standard C5 wheels.
Sweeney brought in his friend Bob Pendleton to handle the multiple wheel changes, and we got to work. The short answer to the question we've been asked, as you'll see in the photos, is that the Z06 wheels and rubber do indeed fit on a C5. Since this is primarily a story about wheel fitments, we'll make a few final comments and get to it. (You can read more about the tires in the accompanying sidebar.) We're dealing with OEM wheel sizes, as well as factory-style repros. There are, of course, a multitude of other wheels and fitments; you should deal with a knowledgeable, reputable dealer or manufacturer if you're looking to venture off the beaten path (i.e., wider-than-stock, as in Z06 or "standard" tires and wheels, or larger diameter, like 19- or 20-inchers-or larger.) All of the wheels featured here are trouble-free, direct bolt-ons. And there's nothing wrong with that; you'll still get the look you want, with the tires you need.
Driving The "Yoke's"
Since it doesn't make much sense to mount wheels without tires, we got on the horn to Yokohama and ordered some Corvette-sized rubber for this project. The guys sent us a set of AVS Sports for the OE Z06 fitment: 295/35ZR18 rear and 275/40ZR17 front. The fronts are actually a bit wider than the OEM-size 265s, but fit fine. Yokohama claims that the AVS Sport provides "unbroken rubber-to-road" contact which increases grip. Granted, our testing was of the seat-of-the-pants variety, but Sweeney and I both came away inpressed. The AVS Sports are quieter (especially compared to the factory-installed Eagle EMT runflats), the grip is excellent, and the "feel" is just as good.
If you're thinking about making this switch, Sweeney had a few words of wisdom. First of all, you can run your stock pressure sensors, with OEM or repro wheels, and people shouldn't be afraid to use them. The sensors probably wouldn't be damaged in a mere flat, CWS warns, but there is a 10 percent chance that they'll be ruined in a more serious blowout. One other thing to remember: if they're not ruined during a flat, running leak-sealing "goo" through the valve stems will end their useful life. Sweeney also had what I found to be an interesting take on the issue of runflats versus non-runflats: "I mostly drive from home to work, and don't really drive anywhere that's out-of-the-way. I have an Auto Club card and a cell phone, and I'm not worried about putting my car on a flatbed. I'd ditch the runflats and enjoy the ride quality of non-runflats."
But if you want to keep the runflats, Yokohama's AVS Sport EMTs are a good choice. The C5-sized rubber features the same basic tread pattern as the "regular" AVS Sports, so grip is good. Sweeney and I agreed that, at least in our informal testing, that the Yokohamas ran quieter than the Goodyears the '99 was wearing, and also had better "feel" (meaning they seemed to have a bit more sidewall flex). Along with the AVS Sport tread pattern, we'd have to say that the Yokohamas are an attractive alternative to the OEM Goodyears.
Easy To Fit
As we said earlier, this article is based on OEM and OEM-style repro Corvette wheels. Since we're dealing with a known quantity, the only measurement we'll deal with here is offset. In short, the offset of a wheel is the distance from its hub mounting surface to the centerline of the wheel. As you can see in the chart, the offset found on the repro wheels is very close, if not identical to, what came on the factory wheels. Where it varies, CWS' Mike Sweeney assures us that the difference is too small to matter. The 2mm difference found on two of the 17x8.5-inch wheels, for instance, only amounts to about 1/16-inch, which won't really affect the wheel fitment.
If you decide to go with wheels that are wider than the stock C5 or Z06 units, you'll also need to deal with backspacing. Backspacing is the distance from the back edge of the wheel to the hub mounting surface, and can be easily measured with a straightedge and a ruler or tape measure. The backspacing on our '99 guinea pig's rear wheel, for instance, is 7 3/4 inches. Again, make sure you get professional help if your motto is "Wider is Better" (sorry, Pontiac).
This chart contains the basic info you'll need to interchange OEM rims or to fit factory style repros. The blank spaces are blank, of course, because GM didn't make the rim size listed. For instance, The General never made an 18x9.5-inch, Z06-style rim. Luckily for us, the aftermarket has stepped in to fill the void, opening up a world of possibilities.