Flow Racers is a reader-supported site. Purchases made through links may earn a commission.

Why Do NASCAR Teams Scrape Tires? (Full Explanation)

You may notice NASCAR teams scrape tires during and after a race. Like everything in NASCAR, there is a reason for it, even if it does not appear to have one from the outside. Because the broadcast or teams may not elaborate on the concept, you may therefore wonder why NASCAR teams scrape tires. 

NASCAR teams scrape tires to monitor how fast their driver’s tires are wearing throughout a race. NASCAR teams use a device called a tire torch to scrape the tires, which allows them to find 5 holes, called wear holes, to measure wear using a tread depth gauge. 

Below, we will dive into full detail on how NASCAR teams scrape tires. We will also discuss why NASCAR teams scrape tires, before talking about what happens to NASCAR tires once they’ve been used in a race.

How Do NASCAR Teams Scrape Tires?

NASCAR teams scrape tires using a tire torch to apply heat to the tire. This heat allows the tire specialist, who is responsible for scraping the tires, to remove the built-up rubber with a scraper to locate 5 wear holes. Teams use measurements from the tires to determine how much they have worn.

During a NASCAR race, tires get hot and pick up debris, along with other pieces of rubber. But they need to get even hotter if the tire specialist is to see how much of the tire’s actual rubber is still clinging to it. Heating the tire with a tire torch allows the tire specialist to distinguish the tire’s rubber from excess rubber and debris the tire picked up during the race. 

Since track conditions may change, the tire specialist must repeat this process multiple times throughout the race. So, every time a driver takes a two or a four-tire pit stop, the tire specialist takes their tire torch to scrape the tires. You will also see them scraping tires following the race, and this allows them to gather useful data about how fast the tires are wearing.

Lifecycle Of A NASCAR Tire

Scraping tires is just one part of the tire specialist’s job. Before any fresh tire finds its way onto a NASCAR car, tire specialists also check tire depth using a tread depth gauge. This gauge lets them check the tire’s depth through the wear holes, and they will report their findings to the engineers and the crew chief. 

NOTE: ‘Tread’ here refers to the usable rubber on the tire, not the ‘treads’ you find on your road car that are shaped like grooves in the tire’s surface, providing more grip on wet and dirty roads. NASCAR tires are slick, meaning they have no ‘treads’ but they do have ‘tread.’

Tire specialists will record the number (usually in millimeters), and they will do the same after the tire wears down and the pit crew removes it. The difference between the two numbers gives the tire specialist an accurate number in millimeters of how much the tire has worn during its life cycle. 

The Tools They Use

NASCAR tire specialists use a digital tread depth gauge to make their measurements, which has a probe on it that they will place, in turn, into each of the 5 small holes in the tire. The gauge has ‘feet’ on it that hold it steadily in place on the top of the tire surface to ensure they get an accurate reading each time. 

The specialist will do this over the 5 holes, which measure the tire tread depth in three regions. They are looking for consistent wear across the inside, center and outside of the contact patch. This is all they do before the tire has been used, but after it has been used, they need to first scrape off any excess rubber or debris the tire has picked up to get an accurate reading.

To do this, they use a blow torch, which heats up the excess rubber and debris to make it easier to scrape off, and a metal scraper. They’ll only do this over the five wear holes, rather than scraping the full tire. But before they do any of this, they’ll also check the tire pressure using a pressure gauge, as this will ensure they can correlate these numbers with any other readings. 

Why Do NASCAR Teams Scrape Tires After A Race?

During a NASCAR race, tires wear down and drivers must make numerous pit stops. Naturally, NASCAR’s tire provider, Goodyear, designs these tires to be used for a roughly predetermined amount of time, although exterior factors like track conditions, driving styles, and even car setups can affect how fast the tires wear. 

Most of the time, Goodyear designs the tires to last between 35 to 100 laps, depending on the size of the track and compounds used in the tires. At larger tracks like Daytona, the tires last far fewer laps than in places like Bristol and Martinsville, which are shorter tracks.

Measuring Tire Wear

To measure the tire wear after a tire has been used, tire specialists will scrape the tires. This lets the team know how fast their tires are wearing, allowing them to tweak their strategies. If the tires are not wearing as they expect, then tire specialists may make pressure adjustments on other sets to account for this. 

The hotter the tire gets, the faster it will wear, and the reason there are multiple wear holes in the tire is that tire specialists must check for wear across three zones, since the tire can heat up differently in different areas

The tire specialist’s goal is to attain consistent levels of wear across all three zones. This assures the tire specialist and the team that the tire is wearing evenly. While the numbers might be different, as different parts of the tires will wear at different rates, consistency and correlation with their expectations is what they’re looking for. 

KEY POINTS

• NASCAR teams scrape tires to allow tire specialists to take measurements of how fast the tires are wearing

• They scrape excess rubber and debris off the tires to allow them to make accurate tread depth measurements

• NASCAR teams will measure tread depth before, during and after races on every set of tires

What Happens To Used NASCAR Tires After A Race?

Used NASCAR tires are recycled after a race by Liberty Tire Recycling. This company recycles all NASCAR tires, from the Cup Series down to regional grassroots racing divisions. Liberty Tire Recycling turns upwards of 100,000 NASCAR tires into fuels, rubberized surfaces and even pavement every year.

NASCAR races consist of 40 cars. Each car uses 4 tires, and teams often go through 5-8 sets of tires per race, depending on track conditions, the track itself, and the number of cautions. This makes for a total of roughly 800-1300 tires per race, not including practice and qualifying sessions. Multiply that over 36 points-paying races and the total is upwards of 30,000 tires per season

And this isn’t even counting ARCA Menards, the Truck Series, or the Xfinity Series. If you were to take the total number of tires used throughout all four series, you easily end up with over 100,000 tires used during a typical NASCAR-sanctioned season, with the total number sometimes hitting upwards of 300,000 across all four series and various grassroots divisions. 

NASCAR In The 21st Century

While many professional sports organizations have gone green or have taken green initiatives in the 21st century, NASCAR had always gotten a bad rap because of the way it guzzled fuel and other resources. Fortunately, NASCAR realized this and took steps to improve its image and decrease its carbon footprint. One way it does this is by recycling used tires. 

NASCAR has partnered with Liberty Tire Recycling to recycle used tires. Besides recycling their own tires, NASCAR has also expanded its program to recycle tires from grassroots organizations nationwide. These tires are recycled into various things, from low-emission fuels and rubberized mulch, to carpet backings and even artificial turf. 

NASCAR in the 21st century has dramatically changed its approach when compared with the distant and even recent past. With Liberty Tire Recycling on board, NASCAR has been able to expand its ability to enhance its sustainability not just in the organization itself, but across the landscape of motorsport

Final Thoughts

NASCAR teams scrape tires so they can measure tire wear. Tire specialists are responsible for measuring tire wear, and they use a tire torch along with a wear depth gauge to measure and monitor the wear. Following each NASCAR event, 1000+ used tires are recycled.