The German-based touring car team, Rotek Racing, brought home their Audi TT RS to a strong win ahead of a 60-car field at the Thunderhill 25 Hours.

Held since 2003 at the undulating northern California circuit, the National Auto Sport Association’s premier race has steadily risen in stature to become the longest club race in the country and one which is increasingly attracting professional teams and drivers.

The field mixes small prototypes, larger specials, GT cars and touring machines in a friendly but fierce mix. As has often been the case at Thunderhill, the fast cars were prototypes in the ESR class.

Rising Italian star Ivan Bellarosa put the JFC Racing Wolf GB08S on the pole, some five seconds clear of his rivals. His team had considerable star power with both Al Unser, Jr. and Al, III on the driving roster. Al, Jr. showed that he has lost none of his touch by setting the race’s fastest lap.

Bellarosa spun on the first lap, which allowed another prototype the Superlite of Team Quick Racing Products to take the lead. Started by Michael Skeen, the Superlite went on to lead overall for more than half of the race.

The best of the GT cars in the early hours was the defending champion Award Motorsports/Ehret Family Winery Porsche 997 GT3 Cup.

The race was started by Tyler McQuarrie with the team staffed by members of Flying Lizard Motorsports. They led the race on occasion and remained a threat but broke a gearbox during the night.

A pre-race favorite the Global Motorsports Group Audi R8 LMS, had to start from the rear after missing qualifying due to having to make repairs after a crash during practice. They recovered nicely and finished fourth overall after a near flawless Sunday morning run.

However, its gearbox failed minutes from the end and had to be pushed across the line, just being clipped for position by the ESR winning Radical.

The prototype challenge disappeared during the night. The steering rack broke on the Superlite and Chris Durbin was unable to make it back to the pits, while the Wolf was poised to take the lead but its engine exploded after it was hit in the rear.

The Rotek Audi was waiting in the wings and inherited a lead of nearly 30 laps from the nearest pursuer, the Barrett Racing Porsche.

The winning Audi’s only delays came from several self-inflicted holds in the penalty box, mostly from yellow flag violations.

The winning drivers were Rob Huff of Great Britain, Robb Holland, Chris Gleason and Jeff Altenburg of the U.S., and Roland Pritzker of Germany, with World Challenge driver Christian Miller as reserve.

The top finishing prototype and winner of the ESR class was the Radical West Racing Radical of Ryan Carpenter, Todd Slusher, Anthony Bullock, Scott Atchison, and Randy Carpenter.

Fifth overall was the Lexus USA-entered IS F. It was one of several significant professional and international entries. The others included the Australian-New Zealand team, Motorsport Services. Veterans of numerous 24 hour races, their Seat Leon Supercopa finished 11th overall.

Mazdaspeed entered three Mazda 6 diesels. These were stock production cars, not the ones that ran this year in GRAND-AM GX class. The Mazdas pitted two teams of dealers versus factory drivers with one of the dealer teams finishing highest in 13th overall.

There was also a Japanese entered Honda CR-Z hybrid from the national endurance series, Super Taikyu. It featured both veteran sports drivers such as Naoki Hattori as well as drifting champion Daijiro Yoshihara.

The other class winners were (E0) Luxury: Don’t Crash Racing, Ford Mustang Boss 302 (Thomas Martin II, Thomas Martin III, Brian Zander and Tom A. Brown); (E1) Honda Research West, Acura ILX (Sage Marie, Lee Niffenegger, Matthew Staal, Scott Nicol, and Michael Tsay), (E3) RJ Racing, Mazda Miata (Rob Gibson, John Gibson, Roger Eagleton, Gary Browne, and Jamie Florence), and (E2) Sector Purple Racing, Mazda Miata: (Kyle Watkins, Robert W. Ames, Daniel Williams, Glen Conser).

The Thunderhill 25 Hours is known for a very eclectic entry and this year’s race included a short track Chevrolet Silverado pickup modified for road racing, a 1970s vintage Mazda RX-3, two motorcycle engine powered Radicals, a Ford Spec Racer, and a Panoz Esperante.

The race featured 13 full-course cautions, mostly for various stranded vehicles. About 35 cars made it to the finish. The weekend was marked by extremely cold, windy, but clear conditions, with temperatures well below freezing during the night and barely climbing towards 40 degrees by day.