For the 2021 season, NASCAR is transitioning from five lug nuts per wheel to a single lug nut per wheel on each of its cars.
The league decided to implement the one lug nut procedure as a result of the introduction of new 18-inch aluminum wheels. Compared to the current wheels on the racecars, the new wheels are three inches longer. With larger wheels, the use of one lug nut versus five increases the stability and durability of the wheels. Additionally, with the use of five lug nuts, there's the chance that not all nuts are tightly secured, increasing the risk of the tires coming off the car.
By switching to a single lug nut, cars should be able to make slightly faster pit stops. It is estimated that the new tires will only take about 0.5 seconds to take off compared to the current tires that take between 0.8 to 1.0 second to remove. As a result, the duration of pit stops could be reduced to only about 10 seconds each. The ability of pit guns to remove one lug nut faster than the current five lug nut design is due to higher torque of the single lug nut. However, since more torque is required to attach the single lug nut, the pit gun will need to remain on the tire for a longer period of time. Therefore, there will not be a dramatic difference compared to the time needed to fasten five lug nuts to the current wheels.
With the change in tires and number of lug nuts per wheel, many question whether the pit stop procedures will differ compared to the current style. Some believe that the procedures will closely resemble those of a Formula 1 or IndyCar open-wheel series race where tire changers are already situated prior to the car stopping. However, John Probst, NASCAR senior vice president of innovation and racing development, ensured fans that there should not be any large changes to the way the pit stop crew carries out their current duties. Probst expressed that crew members will still jump over the walls and need to rush from the right side of the car to the left to change all four tires.
After the change was announced, NASCAR received positive support from the majority of the Cup teams. However, some teams were resistant to the change because of their earned competitive advantage from effectively training crews to change five lug nuts. By switching from five to one lug nut, these teams may lose their supposed advantage. In addition, some argue that the change may reduce the value of the tire changers. However, as previously mentioned, pit stop procedures are not expected to change with the new modification.
While the switch to a single lug nut was a significant change in itself, there are several other alterations that occurred as a result. One change due to the switch is the removal of lug nut penalties and lug nut checks following races. In addition, the five lug nut design required the nuts to be glued to the wheels. The switch prevents teams from having to do this, which will significantly reduce the amount of preparation time that is needed before a race. Furthermore, it should make it easier for pit crews to train because they will be able to avoid gluing the nuts on all of the tires used in the practice sessions.
Another major change is that teams will not need to replace tires as often. With five lug nuts, the tire undergoes more pounding and if the nuts are not securely fastened, the wheel may shake and distort the lug nut holes. Since aluminum wheels tend to be weaker than steel wheels, the use of the single lug nut should help provide increased stability and ensure that the wheel remains fastened to the car.
A lug nut is a metal piece used to fasten a wheel to a car. More specifically, the lug nut secures the hub of the wheel to the studs on the axle of the car. This helps to center the wheel on the axle and hold it in place. Lug nuts are usually made of chrome-plated steel but can also be made of titanium or anodized aluminum which are more lightweight than the steel ones.
To tighten a lug nut, the tools needed include a socket wrench and a torque wrench. However, pit crew members use a power tool called an impact wrench that requires less effort. When using the traditional tools, the lug nut is placed on the wheel and initially tightened with the socket wrench. Following this, the torque wrench is used to finish tightening the nut until the wrench produces a clicking noise, signaling that the nut is tightened all the way.
After a NASCAR race, cars are subjected to a lug nut check to ensure that all of its lug nuts are safely secured. A lug nut penalty is given to a team when a lug nut on a car's wheel is not securely fastened. The cost of the penalty varies based on the number of unsecured lug nuts. For each lug nut that is found not safely secured, team's are fined $10,000.
When wheels had five lug nuts, glue was an essential part of the wheel's functionality. Before each race, the lug nuts were glued to the wheel and the glue was the only thing keeping the lug nuts in place. Furthermore, the amount of glue used is crucial when securing the lug nuts. The glue should not be too dry nor too sticky. In addition, the timing of when the glue is applied is also important to consider depending on the given weather conditions.