He is a staple of the American Le Mans Series during the 2000s and early 2010s, winning the GT class with Porsche in 2002, the LMP2 category in 2006, and taking the overall LMP1 championship as part of the Audi Sport North America works outfit in 2008.

[2] Luhr's GT successes in Europe included class victories at the 2002 and 2003 24 Hours of Le Mans races with Porsche, as well as the 2011 FIA GT1 World Championship title.

In 2000, he moved to the American Le Mans Series, driving a Porsche 911 GT3-R for Dick Barbour Racing and partnering with Dirk Müller.

Luhr began the 2001 season with a class win in the 24 Hours of Daytona, driving for White Lightning Racing.

In 2002, Luhr and Maassen dominated the ALMS GT class, winning seven of ten races, including Sebring and Petit Le Mans.

Luhr also won the GT class at Le Mans, driving with Kevin Buckler and Timo Bernhard for The Racer's Group.

Luhr would finish the season driving with Romain Dumas and take two more victories to end as vice-champion with Maassen.

Luhr also won the 24 Hours Nürburgring overall, driving with Timo Bernhard, Marcel Tiemann, and Mike Rockenfeller.

In 2013, he returned to Muscle Milk in ALMS LMP1 and also won the 24 Hours Nürburgring SP7 class in a Manthey Racing Porsche.

On 26 July 2013, it was announced that Luhr would make his IndyCar Series debut with Sarah Fisher Hartman Racing at Sonoma Raceway in conjunction with RW Motorsports.

Luhr was featured, along with Marion Jones and Marla Streb, in the large format film, Top Speed, hosted by Tim Allen.