From the January, 2007 issue of Stock Car Insider

The Science of NASCAR Tires

Do you own a NASCAR tire, and wonder how you can identify which track and year it was raced? Or do you sit at home and get thoroughly confused while watching the race when the commentators begin to discuss tire compounds? If you're like most casual fans, you probably think that the tires used week-in and week-out on the NASCAR Nextel Cup circuit are identical. If only you knew!

As most of you I'm sure are aware, the Goodyear Eagle racing tire is the official tire used in the NASCAR Nextel Cup and Busch Series circuits. Goodyear holds an exclusive agreement with NASCAR to furnish suitable, safe tires for each track. Given the broad spectrum of race tracks on the NASCAR ciruits, only means that Goodyear must provide a broad range in types of tires.

For example, due to the sharp, low-banked turns of Martinsville Speedway, the cars will lean hard to the right causing higher pressures and stress on the right side tires. Therefore, Goodyear will provide a stronger, more durable right side tire that's exclusive for races held at Martinsville. Typically at all of NASCAR's oval tracks, the right side tires do withstand higher pressures and therefore are larger and have a different make-up than the left side tires.

The surface at Lowe's Motor Speedway was of big concern after the 2005 races there that yielded a historical number of cautions. As a result, Lowe's Motor Speedway re-paved the track this past off-season leaving a new and slicker surface. Thus, Goodyear had to modify the tires used at LMS to accommodate the new surface.

This brings up another crucial point, not only does Goodyear alter the tires between tracks and which side of the car the tire is used, but they also alter the make-up of the tires from year to year. As the engineers in Goodyear's R&D department develop newer compounds, and as track surfaces change (whether it be from aging or from resurfacing), the compounds used in the tires will vary. Thus from year-to-year, as well as, from track-to-track, you can expect to see unique compounds used in the Goodyear Eagle tires.

So how do you identify which designation a tire is? Just like the tires on your car, racing tires have various markings physically embossed in the sidewall of the tire. These markings tell a lot about the tire (from the size of the tire, to the make-up of the tire). The Goodyear Eagle tires have the compound marking physically embossed in large lettering on the front and rear sidewalls of the tire. The compound markings correspond to a particular track for a particular season.

A listing of the 2006 Goodyear Eagle tire designations for the NASCAR Nextel Cup circuit is shown below. Please note the designations vary by track and by which side of the car the tire is used.

The 4-digit designation will be proceeded by a "D" on the sidewall of the tire.  For example, the tires used on the right side of the cars at Martinsville in 2006 will have the designation D4044 embossed on the sidewall.

Again, the designations listed above are unique for the 2006 season.  Tires used in previous years will have a completely different and unique set of designations.

 We hope this will help enlighten you and make you more appreciative of all that goes into the sport of NASCAR.  And for all of you sports memorabilia collectors, please check out our inventory of official race-used NASCAR tires!