25 Hours of Thunderhill

The 25 Hours of Thunderhill is an annual endurance racing event held at the Thunderhill Raceway Park in Willows, California.

From 2003 to 2023, it was sanctioned by the National Auto Sport Association (NASA).^[1]^[2] Starting in 2025, the NASA 25-hour race moved to Ozarks International Raceway in Missouri.^[3]

Since 2025, the 24 Hours of Lemons has held an annual "25 Hours + 1 Minute" endurance race at Thunderhill.^[4]^[5]^[6]

In both its NASA era^[7]^[8]^[9]^[10]^[11] and its Lemons era,^[12]^[13] the series has garnered significant national publicity.

References

↑ "Everything You Wanted to Know About The NASA 25 Hour". National Auto Sport Association. Retrieved 28 June 2026.
↑ Klein, Jamie (2014-12-07). "Davidson Racing Norma wins the 25 Hours of Thunderhill". Motorsport.com. Retrieved 22 February 2017.
↑ Goodwin, Graham (27 March 2025). "NASA 25 Hours Moves To Ozarks International Raceway From Thunderhill For 2025". DailySportsCar. Retrieved 28 June 2026.
↑ "Official Results: The 25:01 2025". 24 Hours of Lemons. Retrieved 28 June 2026.
↑ "Official Results: The 25:01 2026". 24 Hours of Lemons. Retrieved 28 June 2026.
↑ "The 25 Hours and 1 Minute of Thunderhill". Thunderhill Raceway. Retrieved 28 June 2026.
↑ Swan, Tony (30 November 2005). "2005 Thunderhill 25-Hour". Car and Driver. Retrieved 28 June 2026.
↑ Mitani, Sam (9 December 2009). "Running in the 7th Annual 25 Hours of Thunderhill". Road & Track. Retrieved 28 June 2026.
↑ Jones, Matthew (13 March 2014). "NASA 25 Hours of Thunderhill – Surviving Thunder Hill". MotorTrend. Retrieved 28 June 2026.
↑ "Rotek Racing Audi TT RS wins 25 Hours of Thunderhill". Autoweek. 8 December 2013. Retrieved 28 June 2026.
↑ Sharp, Tim (29 November 2024). "Night Terrors: Staying Alive at the Thunderhill 25". Grassroots Motorsports. Retrieved 28 June 2026.
↑ Glucker, Jeff (27 June 2025). "The 25 Hours & 1 Minute of Thunderhill was Awesome (…and also hell on earth )". Hooniverse. Retrieved 28 June 2026.
↑ Gilboy, James (28 June 2025). "We Entered the Electric Lemons Endurance Test and, Well…". Car and Driver. Retrieved 28 June 2026.

External links

Official website

[nasa-1] "Everything You Wanted to Know About The NASA 25 Hour". National Auto Sport Association. Retrieved 28 June 2026.

[2] Klein, Jamie (2014-12-07). "Davidson Racing Norma wins the 25 Hours of Thunderhill". Motorsport.com. Retrieved 22 February 2017.

[3] Goodwin, Graham (27 March 2025). "NASA 25 Hours Moves To Ozarks International Raceway From Thunderhill For 2025". DailySportsCar. Retrieved 28 June 2026.

[4] "Official Results: The 25:01 2025". 24 Hours of Lemons. Retrieved 28 June 2026.

[5] "Official Results: The 25:01 2026". 24 Hours of Lemons. Retrieved 28 June 2026.

[6] "The 25 Hours and 1 Minute of Thunderhill". Thunderhill Raceway. Retrieved 28 June 2026.

[7] Swan, Tony (30 November 2005). "2005 Thunderhill 25-Hour". Car and Driver. Retrieved 28 June 2026.

[8] Mitani, Sam (9 December 2009). "Running in the 7th Annual 25 Hours of Thunderhill". Road & Track. Retrieved 28 June 2026.

[9] Jones, Matthew (13 March 2014). "NASA 25 Hours of Thunderhill – Surviving Thunder Hill". MotorTrend. Retrieved 28 June 2026.

[10] "Rotek Racing Audi TT RS wins 25 Hours of Thunderhill". Autoweek. 8 December 2013. Retrieved 28 June 2026.

[11] Sharp, Tim (29 November 2024). "Night Terrors: Staying Alive at the Thunderhill 25". Grassroots Motorsports. Retrieved 28 June 2026.

[12] Glucker, Jeff (27 June 2025). "The 25 Hours & 1 Minute of Thunderhill was Awesome (…and also hell on earth )". Hooniverse. Retrieved 28 June 2026.

[13] Gilboy, James (28 June 2025). "We Entered the Electric Lemons Endurance Test and, Well…". Car and Driver. Retrieved 28 June 2026.

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Automobile endurance races
24 hours	24 Hours of Le Mans 24 Hours of Daytona Nürburgring 24 Hours Spa 24 Hours Dubai 24 Hour Fuji 24 Hours 24 Hours of Zolder 24 Hours of Barcelona 2CV 24 Hour Race 24H Silverstone Longest Day of Nelson 24 Hours of Chamonix Willhire 24 Hour Bathurst 24 Hour Tokachi 24 Hours 24 Hours of Portimão
12 hours	12 Hours of Sebring Bathurst 12 Hour 12 Hours of Mugello 12 Hours of Spa-Francorchamps Sepang 12 Hours 12 Hours of Tarumã 992 Endurance Cup 12 Hours of Kuwait 12 Hours of Hungary Coppa Florio 12 Hours of Sicily 12 Hours at the Point 12 Hours of Brno 12 Hours of Reims Gulf 12 Hours Rothmans 12 hours
10 hours	Petit Le Mans Qatar 1812 km 10 Hours of Messina
9 hours	Kyalami 9 Hours
8 hours	8 Hours of Bahrain Indianapolis 8 Hour Texas 8 Hour California 8 Hours
6 hours	Lone Star Le Mans 6 Hours of Barcelona 6 Hours of Fuji 6 Hours of Imola 6 Hours of São Paulo 6 Hours of Silverstone 6 Hours of Spa-Francorchamps 6 Hours of Monza 6 Hours of Road America (IMSA) 6 Hours of Watkins Glen 6 Hours of Abu Dhabi 6 Hours of Bogotá Bathurst 6 Hour 6 Hours of Atlanta 6 Hours of Donington 6 Hours of Indianapolis (IMSA) 6 Hours of Jeddah 6 Hours of Mexico 6 Hours of Nürburgring 6 Hours of Perth 6 Hours of Portimão 6 Hours of Rome 6 Hours of Zhuhai Mid-Ohio 6 Hours Monterey 6 Hours Mosport 6 Hours Riverside 6 Hours
4 Hours	4 Hours of Abu Dhabi 4 Hours of Barcelona 4 Hours of Dubai 4 Hours of Imola 4 Hours of Jerez 4 Hours of Le Castellet 4 Hours of Portimão 4 Hours of Sepang 4 Hours of Silverstone 4 Hours of Spa-Francorchamps 4 Hours of Aragón 4 Hours of Buriram 4 Hours of Estoril 4 Hours of Fuji 4 Hours of Monza 4 Hours of Mugello 4 Hours of Red Bull Ring 4 Hours of Shanghai 4 Hours of Shanghai (AsLMS) 4 Hours of The Bend 4 Hours of Zhuhai
2 hours	TCR European Endurance
1000 miles	Mil Milhas Brasil 1000 Miles of Sebring Mille Miglia
1000 km	1006 km Palanga 1000 km Paul Ricard Bathurst 1000 Baja 1000 Sepang 1000 km Suzuka 1000 km 1000 km Brands Hatch 1000 km Buenos Aires 1000 km Istanbul 1000 km Jarama 1000 km Le Mans (Bugatti) 1000 km Mosport 1000 km Okayama 1000 km Paris Race of a Thousand Years
Other	25 Hours of Spa 25 Hours of Thunderhill Carrera Panamericana Charge of the Headlight Brigade Targa Florio TCR Spa 500 Laps or 23 Hours The 2904
Defunct races are indicated in italics