Many newer Corvettes-including...
Many newer Corvettes-including our C5-have a tire-pressure-monitoring system installed from the factory. When replacing the wheels on one of these cars, you'll need to transfer the sensors from your original rims onto the new ones. New grommet kits are available, if needed, to help reseal your sensors.
The W refers to the maximum velocity the tire can sustain for 10 minutes without failing. This component is only found on tires with a Z speed rating.
| Speed Rating Chart |
| Code | MPH | KPH |
| L | 75 | 120 |
| M | 81 | 130 |
| N | 87 | 140 |
| P | 94 | 150 |
| Q | 100 | 160 |
| R | 106 | 170 |
| S | 112 | 180 |
| T | 118 | 190 |
| U | 124 | 200 |
| H | 130 | 210 |
| V | 149 | 240 |
| Z | Over 149 | Over 240 |
| W | 168 | 270 |
| (W) | Over 168 | Over 270 |
| Y | 186 | 300 |
| (Y) | Over 186 | Over 300 |
When having tires installed...
When having tires installed on your Corvette, make sure the equipment the shop is using will not scratch or damage your wheels.
There are a few other codes on the tire that you should know, such as the treadwear code, traction grades, and temperature grades.
The treadwear code is a three-digit number located on the sidewall. This is a comparative rating designed to give you an idea of the expected tread life of a tire. These grades are based on actual road miles, in which the test tire is run on a vehicle alongside an identical vehicle fitted with a control tire with a treadwear rating of 100. These vehicles run a total of 7,200 miles on a 400-mile test loop in Texas. Both the test and control tires' wear are measured periodically during and at the conclusion of the test. The tire manufacturers then assign a treadwear grade based on the observed wear rates.
Note how this tire machine...
Note how this tire machine captures the wheel from the inside, eliminating the possibility of damage.
Treadwear ratings typically begin at 100 and increase or decrease in increments of 10, depending on the tire's expected tread life. A rating of 100 represents an expected life of 30,000 miles. Using this system, a tire with a treadwear rating of 150 should have a 50 percent longer tread life, or 15,000 additional miles over the base tire rating.
That's how the system is supposed to work, anyway. But because the Department of Transportation isn't involved in tire testing, the agency depends solely on the manufacturers to test their own tires and report the results. Accordingly, treadwear ratings are open to some degree of interpretation, and can thus be legally manipulated for marketing purposes. Don't be fooled if you see a tire with a treadwear rating that seems extreme. A good rule of thumb is that soft-compound tires--including most high-performance units--will wear faster than hard-compound ones.