The 2003 Infineon Grand Prix of Sonoma was the third race of the 2003 American Le Mans Series season. It took place at Infineon Raceway, California on July 27, 2003.

This race marked the first time in American Le Mans Series history since the introduction of the two separate Le Mans Prototype classes in 2001 that the smaller of the two won a race overall. The LMP675 class Dyson Lola-MG defeated the LMP900 class Joest Audi by a margin of 3.7 seconds.

Official results

Class winners in bold. Cars failing to complete 75% of winner's distance marked as Not Classified (NC).

Pos	Class	No	Team	Drivers	Chassis	Tyre	Laps
					Engine
1	LMP675	16	Dyson Racing	Butch Leitzinger James Weaver	MG-Lola EX257	G	102
					MG (AER) XP20 2.0L Turbo I4
2	LMP900	1	Infineon Team Joest	Marco Werner Frank Biela	Audi R8	M	102
					Audi 3.6L Turbo V8
3	LMP900	38	ADT Champion Racing	Johnny Herbert JJ Lehto	Audi R8	M	102
					Audi 3.6L Turbo V8
4	LMP900	27	Doran Lista Racing	Didier Theys Bill Auberlen	Dallara SP1	M	102
					Judd GV5 5.0L V10
5	LMP900	10	JML Team Panoz	Olivier Beretta Gunnar Jeannette	Panoz LMP01 Evo	M	101
					Élan 6L8 6.0L V8
6	LMP900	11	JML Team Panoz	Benjamin Leuenberger David Saelens	Panoz LMP01 Evo	M	101
					Élan 6L8 6.0L V8
7	LMP675	20	Dyson Racing	Chris Dyson Andy Wallace	MG-Lola EX257	G	100
					MG (AER) XP20 2.0L Turbo I4
8	GTS	3	Corvette Racing	Ron Fellows Johnny O'Connell	Chevrolet Corvette C5-R	G	97
					Chevrolet LS7-R 7.0L V8
9	GTS	4	Corvette Racing	Kelly Collins Oliver Gavin	Chevrolet Corvette C5-R	G	97
					Chevrolet LS7-R 7.0L V8
10	GTS	80	Prodrive	David Brabham Jan Magnussen	Ferrari 550-GTS Maranello	M	96
					Ferrari 5.9L V12
11	LMP900	30	Intersport Racing	Clint Field Rick Sutherland	Lola B2K/10B	G	94
					Judd GV4 4.0L V10
12	GTS	88	Prodrive	Tomáš Enge Peter Kox	Ferrari 550-GTS Maranello	M	94
					Ferrari 5.9L V12
13	GT	23	Alex Job Racing	Lucas Luhr Sascha Maassen	Porsche 911 GT3-RS	M	93
					Porsche 3.6L Flat-6
14	GT	24	Alex Job Racing	Jörg Bergmeister Timo Bernhard	Porsche 911 GT3-RS	M	93
					Porsche 3.6L Flat-6
15	GT	35	Risi Competizione	Anthony Lazzaro Ralf Kelleners	Ferrari 360 Modena GTC	M	93
					Ferrari 3.6L V8
16	GT	66	The Racer's Group	Kevin Buckler Cort Wagner	Porsche 911 GT3-RS	M	93
					Porsche 3.6L Flat-6
17	GT	31	Petersen Motorsport White Lightning Racing	Craig Stanton Johnny Mowlem	Porsche 911 GT3-RS	M	92
					Porsche 3.6L Flat-6
18	LMP675	18	Essex Racing	David McEntee Jason Workman	Lola B2K/40	P	92
					Nissan (AER) VQL 3.0L V6
19	GT	79	J3 Racing	David Murry Justin Jackson	Porsche 911 GT3-RS	M	91
					Porsche 3.6L Flat-6
20	GT	43	Orbit Racing	Leo Hindery Peter Baron	Porsche 911 GT3-RS	M	91
					Porsche 3.6L Flat-6
21	GT	67	The Racer's Group	Michael Schrom Pierre Ehret	Porsche 911 GT3-RS	M	90
					Porsche 3.6L Flat-6
22	GTS	0	Team Olive Garden	Emanuele Naspetti Mimmo Schiattarella	Ferrari 550 Maranello	P	90
					Ferrari 6.0L V12
23	GT	42	Orbit Racing	Joe Policastro Joe Policastro Jr.	Porsche 911 GT3-RS	M	89
					Porsche 3.6L Flat-6
24	GT	89	Inline Cunningham Racing	Oswaldo Negri Jr. Scott Bader	Porsche 911 GT3-RS	Y	87
					Porsche 3.6L Flat-6
25	GT	28	JMB Racing USA	Stéphane Grégoire Eliseo Salazar	Ferrari 360 Modena GTC	P	87
					Ferrari 3.6L V8
26	GT	61	P.K. Sport	Keith Alexander Vic Rice	Porsche 911 GT3-R	P	87
					Porsche 3.6L Flat-6
27	GT	63	ACEMCO Motorsports	Terry Borcheller Shane Lewis	Ferrari 360 Modena GTC	Y	87
					Ferrari 3.6L V8
28	GT	68	The Racer's Group	Marc Bunting Chris Gleason	Porsche 911 GT3-RS	M	81
					Porsche 3.6L Flat-6
29 DNF	GT	60	P.K. Sport	Robin Liddell Alex Davison	Porsche 911 GT3-RS	P	72
					Porsche 3.6L Flat-6
30 DNF	GTS	71	Carsport America	Aaron Povoledo Jean-Philippe Belloc	Dodge Viper GTS-R	P	71
					Dodge 8.0L V10
31 DNF	LMP900	12	American Spirit Racing	Michael Lewis Tomy Drissi	Riley & Scott Mk III C	D	45
					Lincoln (Élan) 5.0L V8
32 DNF	GT	33	ZIP Racing	Andy Lally Spencer Pumpelly	Porsche 911 GT3-RS	D	44
					Porsche 3.6L Flat-6
33 DNF	GT	29	JMB Racing USA	Andrea Garbagnati Ludovico Manfredi	Ferrari 360 Modena GTC	P	31
					Ferrari 3.6L V8
34 DNF	GT	03	Hyper Sport	Joe Foster Brad Nyberg Rick Skelton	Panoz Esperante GT-LM	P	28
					Élan 5.0L V8
35 DNF	LMP675	56	Team Bucknum Racing	Jeff Bucknum Bryan Willman Chris McMurry	Pilbeam MP91	D	24
					Willman (JPX) 3.4L V6
DNS	LMP675	37	Intersport Racing	Jon Field Duncan Dayton	MG-Lola EX257	G	-
					MG (AER) XP20 2.0L Turbo I4

Statistics

• Pole Position - #16 Dyson Racing - 1:23.085
• Fastest Lap - #16 Dyson Racing - 1:24.229
• Distance - 415.307 km
• Average Speed - 150.145 km/h