NASCAR Next-Gen Cup Series Car will Utilize a Single Lugnut System, Aluminum Wheel

NASCAR announced Monday that the next-gen NASCAR Cup Series car currently in development will change to a single lugnut system moving away from the traditional 5 lugnut system.

The single lugnut system is similar to what is used in the IndyCar Series. The new single lugnut system was tested in the most recent next-gen car test at Auto Club Speedway on Monday.

The primary driver for the change was another change the sanctioning body is implementing. The new car will change from the traditional 15″ steel wheel to an 18″ forged aluminum wheel.

NASCAR Senior Vice President of Innovation and Racing Development, John Probst, stated the move to the single lugnut system is for durability with the new wheel type. “For us we felt like from a standpoint of the wheel is that we wanted to get to an 18-inch wheel, an aluminum wheel,” Probst said. “Once you get to an 18-inch aluminum wheel, the next step for us is to make sure that from a durability standpoint under racing conditions is that it will accept the durability that we need to finish races and then also finish multiple races. To do that, the single nut was our only option.”

Aluminum wheel are more sensitive to loose lugnuts than steel wheels. Given that teams are attempting to complete pitstops as quickly as possible, there is a greater risk of the car leaving with loose lugnuts. This would be very concerning given the new aluminum style wheel. “The steel wheel is more forgiving and can handle loose wheels a little bit better,” Probst said. “When we get to the aluminum wheel, we did some durability studies and if you leave lug nuts loose on an aluminum wheel, you reduce the durability of the wheel by around 30%. It’s more of, the aluminum wheel has less tolerance to loose lug nuts, so when we have one, there really is only one thing to concentrate on, and that is to get that lug nut tight. Then everything else from a durability standpoint is fine.”

While many fans responded harshly to the change on social media, some citing NASCAR is “moving more away from stock”, while others stated concern for the change in pit stops.

Probst addressed some of those concerns saying, “I think from a fan standpoint, the choreography of the pit stop will look unchanged. I think that a lot of times when we say single lug nut, people fear that it’s an open-wheel style pit stop where people will be on their knees waiting for the car to come in. We don’t intend to change anything with respect to how the pit-stop flow is executed. There will still be guys coming off the wall, there will still be a premium for that athlete to come off the wall, get to the right side of the car, make that tire change, get over to the left side of the car and make the tire change. From the look and feel of the pit stop, we don’t see any significant changes.”