How Big Are NASCAR Tires? (Next Gen Dimensions Explained)

NASCAR’s Next Gen car changed the sport’s landscape forever. When you take just one look at the new car, you can tell there are several differences regarding the wheels and tires. Knowing this, you may therefore wonder how big NASCAR tires are on new Next Gen car. 

NASCAR tires measure 18 inches (46 centimeters) in diameter on the Next Gen car and they weigh 26 pounds (12 kg). With the wheel rim added, these tires weigh 48 pounds (22 kg), and their circumference measurements often vary between 88 inches (223.5 cm) and 90 inches (228.6 cm). 

Below, we will elaborate further on how much NASCAR tires weigh and go into deeper detail regarding their length, circumference, and rubber thickness. We will break down why NASCAR made the changes, and provide a full explanation of their dimensions. 

How Much Do NASCAR Tires Weigh?

NASCAR tires weigh 26 pounds (12 kg). The Next Gen car’s rims weigh an additional 22 lbs (10 kg), so the tire plus the rim weighs 48 lbs (22 kg), with all 4 tires making up about 6% of the car’s total weight. This is what the tire carriers are carrying around with them at every NASCAR pit stop.

KEY FACT: Since NASCAR pit crews carry two tires at a time, they are hauling 96 pounds (44 kg) of rubber and aluminum!

When NASCAR introduced the Next Gen car before the 2022 season, one look would tell you just how much the car had changed, and the tires were no exception. Gone were the 15 inch (38 centimeter) wheels, which necessitated different tires from Goodyear. So with a new length came a different tire, which also meant a different tire weight. 

Since the tires and rims are bigger, you may think they weigh more than their smaller counterparts. However, this assumption is wrong, as the old tires and rims weighed a combined 52 pounds (23.5 kg). How is this possible? If you know anything about metals, you will know that smaller doesn’t always equate to lighter. 

And this is the case with NASCAR tires and their rims. The old rims were steel, and the Next Gen rims are aluminum. Since we know steel is a harder, denser metal than aluminum, it will weigh more even if it is a few inches smaller in diameter. Steel is also more durable than aluminum. So on a NASCAR car, why replace them with something that’s less durable?

Why NASCAR Changed The Tires

NASCAR wanted to go with the lighter aluminum rims for a couple of reasons. For one, aluminum is cheaper than steel. And for another, NASCAR wanted the cars to better resemble their showroom counterparts, and aluminum allowed them to do that. Also, the job of a NASCAR pit crew member is one of the most physically demanding jobs out there. 

And a larger tire requiring a larger steel rim would have weighed over 60 pounds (27 kg). The lighter aluminum tires were easier for tire carriers to handle, since in today’s NASCAR pit crew, you have one tire carrier handling all four tires, so carrying two tires at a time weighing so much would take even more of a toll on their bodies. 

How Wide Are NASCAR Tires?

NASCAR tires are 18 inches (46 cm) wide, to fit around the 18 inch (46 cm) BBC aluminum rims. NASCAR Next Gen tires are wider than the old 15 inch (38 cm) tires. Their tread width measures 11.5 inches (29 cm) on the slick tire while the wet tire measures 9 inches (23 cm) wide. 

When you look at a NASCAR Next Gen tire and compare it to the Gen 6 model, you will see the clear differences in the sidewalls, with the Generation 6 car having the shorter wheel diameter, which required a thicker sidewall. The added width on the Next Gen tires gives them better contract with the track, providing better grip, which equals better handling. 

A Word On Next Gen Tire Circumference

While the tires have similar lengths and widths, the truth is that the same does not hold true for circumference, meaning the sidewalls can clock in at differing lengths to achieve a desired circumference. This often varies by track. Factors that determine circumference can include the time of the race (which influences the track temperature), and how each tire responds to the track surface. 

Take, for example, the tire circumference at Charlotte Motor Speedway in the 2022 season. For the Coca-Cola 600, the tires measured in at a circumference of 89.76 inches (227.9 cm) on the right-hand side. The left-side tires, however, clocked in at 88.74 inches (225.3 cm). 

At the short Martinsville Speedway, the right-side tires measured 89.69 inches (227.8 cm) and 88.54 inches on the left (224.9 cm). As you can see, the discrepancies are not huge, and to the naked eye, they are not noticeable. However, NASCAR is a sport of fine margins, and the smallest of changes can affect how the cars handle.

How Thick Is The Rubber On A NASCAR Tire?

The rubber on a NASCAR tire is 3/32 inches (2.4 mm) thick, which is very thin for a tire. This is much thinner than the 11/32 inches (8.7 mm) you see on production cars. This is the main reason NASCAR drivers have to pit for new tires so often, as the rubber wears so fast.

NASCAR Tire Dimensions 

Weight Without Rim26 lbs / 12 kg
Weight With Rim48 lbs / 22 kg
Rim Diameter18 inches (46 cm)
Tire Diameter28 inches (71 cm)
Dry Tread Width11.5 inches (29 cm)
Wet Tread Width9 inches (23 cm)
Circumference88-90 inches (224-229 cm)
Rubber Thickness3/32 inches (2.4 mm)

Final Thoughts

NASCAR Next Gen tires measure quite differently than their Generation 6 counterparts. To better resemble measurements of a road car, NASCAR went with a larger yet lighter tire thanks to the aluminum rims in favor of steel. The Next Gen tires are wider than their predecessors.