NASCAR Car Inspection Process

NASCAR Car Inspection Process

NASCAR inspects all of its cars to ensure driver safety and prevent cheating. If a car fails its inspection, the team can be subject to penalties. Keep reading to learn how the NASCAR car inspection process works.


The NASCAR car inspection process is the mandatory examination of cars before and after each race. A pre-race inspection is performed on all cars and takes about three hours to complete. It consists of five different inspection stations at which visual inspections, optical scans, and safety certifications take place. The top three finishers in each race are also subject to a post-race inspection, which takes about an hour and a half for all three cars. The post-race inspection consists of three inspection stations followed by a complete teardown of the cars.

Pre-Race Inspection Stations

Here are the five stations that are included in a NASCAR pre-race inspection:

  1. The elevated car is visually inspected from below to examine the nose, undercarriage, and interior.
  2. The body is visually inspected using a hand-held template.
  3. The weight and height of the car are measured.
  4. The Hawkeye inspection system is used to perform an optical scan of the chassis and body.
  5. Holding blocks are removed for a final inspection of safety equipment.

NASCAR Hawkeye Inspection System

The NASCAR Hawkeye inspection system is an advanced optical scanner that was added to the pre-race inspection in the 2018 season. Also known as the Optical Scanning System, or OSS, the system consists of eight projectors and 17 cameras, one of which is positioned below the car. In a process that takes about 30 seconds, the projectors display patterns of dots on the car, which the cameras track and record.

Using the data from the cameras, the Hawkeye system creates a “point cloud” which forms a 3D model of the car. This model is then compared to a CAD diagram of the car to ensure compliance. Teams are allowed a .150-inch tolerance on metal surfaces and a .200-inch tolerance on glass surfaces.

Post-Race Inspection

Following a race, the top three finishers must complete a post-race inspection. This inspection uses the final three stations of the pre-race inspection, skipping the initial visual inspection and hand-held template. Greater tolerances are given in the post-race inspection to allow for damage incurred during the race.

After going through these stations, the cars are then put through a complete teardown in which every component is inspected. Only after the post-race inspection can the finish be certified. This is the reason for the hour-and-a-half delay between the end of a race and the results becoming official.


If a car fails its pre-race inspection twice, it must start the race at the rear of the field, and that team’s crew chief is ejected from the race. A third failed pre-race inspection results in a pass-through penalty on Lap 1, typically causing the car to go at least a lap down at the beginning of the race.

If a car fails a post-race inspection, it is automatically disqualified. If the failure is deemed the result of an accidental lapse, the punishment is a deduction of 10 to 40 points, the suspension of a crew member for one to three races, and a fine between $25,000 and $75,000.

If the inspectors determine that failing a post-race inspection is the result of an illegal attempt to gain a competitive advantage, the punishment is more severe. The team receives a penalty of at least 75 points, a six-race team member suspension, and a fine between $100,000 and $200,000. Even more severe penalties can be levied on repeat offenders or those that show a trend of cheating.

NASCAR Car Inspection Rules Summary

  • All cars must complete a five-station pre-race inspection to ensure their compliance with NASCAR standards and regulations.
  • The three top finishers are subject to a three-station post-race inspection followed by a complete teardown.
  • There is no penalty for failing the first pre-race inspection, but a second inspection must be passed before the car can race.
  • A second failed pre-race inspection results in a starting position penalty and the crew chief’s ejection from the race.
  • A third failed pre-race inspection results in a pass-through penalty on Lap 1.
  • A failed post-race inspection results in automatic disqualification along with the suspension of crew members, point penalties, and monetary fines.
  • The penalties for a failed post-race inspection are more severe if the violation is deemed to be an intentional attempt to gain an unfair competitive advantage.


How does the NASCAR inspection process work?

Before any car can race in a NASCAR event, it must be inspected and approved by a NASCAR official. Inspectors carefully examine each car before a race, making sure that every part and system conforms with NASCAR regulations. If a car fails its pre-race inspection, the team must make the required changes and pass a second inspection before the car will be allowed to race. The cars are also subject to a post-race inspection to ensure that no regulations or rules have been violated.

Does NASCAR inspect every car after a race?

Only the top three finishers are inspected after a NASCAR race. Every car must complete a pre-race inspection, but the rest of the field is exempt from the post-race inspection. In addition to three stations of measurements and scans, the post-race inspection requires a complete teardown of the cars.

What happens if the car fails post-race inspection?

If the car fails NASCAR’s post-race inspection, it is subject to disqualification and penalties. An example of this was in 2007 when NASCAR found that the team for Jeff Gordon’s #24 car had modified the fenders in an area that was not permitted under NASCAR rules. As a punishment, the team was fined $100,000 and got a 100-point penalty, making for a costly mistake. More recently, Denny Hamlin was disqualified and stripped of his win after an unauthorized part was found on his car after the 2022 M&M's Fan Appreciation 400 at Pocono Raceway.