Top 10 Cheating Scandals in NASCAR History

Biggest Cheating Scandals in NASCAR History

Dale Earnhardt and Dale Earnhardt Sr.

10. Smokey Yunick’s Rulebook Rebellion

Smokey once left the garage with 11 fuel lines after NASCAR removed ten. His creativity forced NASCAR to rewrite the rulebook — literally.

9. Carl Long’s “Too Big” Engine (2009)

An oversized engine at the All-Star Race earned Long a $200,000 fine and suspension — devastating for a small team.

8. Toyota’s Intake Manifold Trick (2007)

Toyota was caught modifying intake manifolds to gain horsepower. Massive penalties followed during its early Cup Series years.

7. Clint Bowyer’s Richmond SpinGate (2013)

A suspicious spin helped teammate Martin Truex Jr. make the playoffs. NASCAR responded by overhauling the playoff system.

6. Junior Johnson’s Fuel Line Trick

Hidden fuel lines gave cars extra range. It wasn’t illegal — until NASCAR caught on and banned it.

5. Richard Petty’s Illegal Engine (1983)

Petty won at Charlotte before NASCAR found an illegal engine. The King lost the win, shocking the sport.

4. Chad Knaus’ Repeated Infractions

From illegal body modifications to suspension tricks, Knaus pushed the limits more than anyone — and still won seven titles.

3. Jeremy Mayfield’s Drug Test Fallout (2009)

After failing a drug test, Mayfield claimed NASCAR set him up. Lawsuits, bans, and chaos followed.

2. Dale Earnhardt’s Roof Flap Tricks

Subtle body manipulation improved aerodynamics. NASCAR suspected it for years but never fully proved it.

1. Team Orders at Talladega (Manipulation Era)

Manufacturers allegedly coordinated finishes to protect playoff drivers — leading to penalties and stricter radio rules.