| | No. | Class | Team | Drivers | Car |
| 1 | 1 | LMP1 | Audi Sport North America | Allan McNish
Tom Kristensen
Rinaldo Capello | Audi R10 |
| 2 | 2 | LMP1 | Audi Sport North America | Marco Werner
Frank Biela
Emanuele Pirro | Audi R10 |
| 3 | 12 | LMP1 | Autocon Motorsports | Michael Lewis
Chris McMurry
Bryan Willman | Lola B01/60 AER |
| 4 | 37 | LMP1 | Intersport Racing | Jon Field
Clint Field
Richard Berry | Creation CA06/H Judd |
| 5 | 6 | LMP2 | Penske Motorsports | Sascha Maassen
Ryan Briscoe
Emmanuel Collard | Porsche RS Spyder |
| 6 | 7 | LMP2 | Penske Motorsports | Timo Bernhard
Romain Dumas
Helio Castroneves | Porsche RS Spyder |
| 7 | 8 | LMP2 | B-K Motorsports | Jamie Bach
Ben Devlin
Rafael Matos | Lola B07/40 Mazda |
| 8 | 9 | LMP2 | Highcroft Racing | David Brabham
Stefan Johansson
Duncan Dayton | Courage Acura
ARX-01a Acura |
| 9 | 15 | LMP2 | Lowe's Fernandez Racing | Adrian Fernandez
Luis Diaz
David Martinez | Lola B06/43 Acura |
| 10 | 16 | LMP2 | Dyson Racing Team | Andy Wallace
Butch Leitzinger
Andy Lally | Porsche RS Spyder |
| 11 | 20 | LMP2 | Dyson Racing Team | Chris Dyson
Guy Smith | Porsche RS Spyder |
| 12 | 26 | LMP2 | Andretti Green Racing Inc. | Bryan Herta
Dario Franchitti
Tony Kanaan | Courage Acura
ARX-01a Acura |
| 13 | 27 | LMP2 | Horag Racing | Fredy Lienhard
Didier Theys
Eric van de Poele | Lola B05/40 Judd |
| 14 | 3 | GT1 | Corvette Racing | Johnny O'Connell
Jan Magnussen
Ron Fellows | Corvette C6.R |
| 15 | 4 | GT1 | Corvette Racing | Oliver Gavin
Olivier Beretta
Max Papis | Corvette C6.R |
| 16 | 63 | GT1 | Team Modena | Antonio Garcia
Liz Halliday
Darren Turner | Aston Martin DBR9 |
| 17 | 10 | GT2 | Konrad Motorsport | Philip Collin
TBA | Porsche 911 GT3-RS |
| 18 | 18 | GT2 | Rahal Letterman Racing | Ralf Kelleners
Tom Milner
Graham Rahal | Porsche 997 GT3-RSR |
| 19 | 21 | GT2 | Panoz Team PTG | Bill Auberlen
Joey Hand
Tom Kimber-Smith | Panoz Esperante GTLM |
| 20 | 22 | GT2 | Panoz Team PTG | Scott Maxwell
Bryan Sellers
Ross Smith | Panoz Esperante GTLM |
| 21 | 24 | GT2 | JMB Racing | Ben Aucott
Joe Macari
Rob Wilson | Ferrari 430 GTC |
| 22 | 31 | GT2 | Petersen / White Lightning | Tomas Enge
Tim Bergmeister
Memo Gidley | Ferrari 430 GTC |
| 23 | 32 | GT2 | Corsa / White Lightning | Maurizio Mediani
Rui Aguas
Jose Maria Lopez | Ferrari 430 GTC |
| 24 | 44 | GT2 | Flying Lizard Motorsports | Lonnie Pechnik
Seth Neiman
Darren Law | Porsche 997 GT3-RSR |
| 25 | 45 | GT2 | Flying Lizard Motorsports | Johannes van Overbeek
Jorg Bergmeister
Marc Lieb | Porsche 997 GT3-RSR |
| 26 | 53 | GT2 | Robertson Racing LLC | David Robertson
Andrea Robertson
Arie Luyendyk Jr. | Panoz Esperante GTLM |
| 27 | 54 | GT2 | Team Trans Sport Racing | Tim Pappas
Terry Borcheller
Marc Basseng | Porsche 997 GT3-RSR |
| 28 | 61 | GT2 | Risi Competizione | Tracy Krohn
Nic Jonsson
Colin Braun | Ferrari 430 GTC |
| 29 | 62 | GT2 | Risi Competizione | Mika Salo
Jaime Melo
Johnny Mowlem | Ferrari 430 GTC |
| 30 | 71 | GT2 | Tafel Racing | Wolf Henzler
Robin Liddell
Patrick Long | Porsche 997 GT3-RSR |
| 31 | 73 | GT2 | Tafel Racing | Jim Tafel
Dominik Farnbacher
Ian James | Porsche 997 GT3-RSR |
| 32 | 77 | GT2 | Autoracing Club Bratislava | Miroslav Konopka
Bo McCormick
Mauro Casadei | Porsche 911 GT3-RS |
| 33 | 85 | GT2 | Farnbacher Loles Motorsports | Pierre Ehret
Lars-Erik Nielsen
Dirk Werner | Porsche 997 GT3-RSR |
| 34 | 86 | GT2 | Spyker Squadron | Peter Kox
Jarek Janis | Spyker C8 |
