| Race Title: | Indycar Grand Prix of Sonoma |
| Series Long: | IndyCar Series |
| Series Short: | ICS |
| Venue: | Sonoma Raceway |
| First Race: | 1970 |
| First Series Race: | 2005 |
| Last Race: | 2018 |
| Distance: | 202.725 miles (326.254 km) |
| Laps: | 85 |
| Previous Names: | Golden State 150 (1970) Argent Mortgage Indy Grand Prix (2005) Indy Grand Prix of Sonoma (2006, 2010–2011) Motorola Indy 300 Pres. by Jackson Rancheria Casino & Hotel (2007) Peak Antifreeze & Motor Oil Indy Grand Prix of Sonoma County (2008) Peak Antifreeze Grand Prix of Sonoma County (2009) GoPro Indy Grand Prix of Sonoma (2012–2014) GoPro Grand Prix of Sonoma (2015–2017) INDYCAR Grand Prix of Sonoma (2018) |
| Most Wins Driver: | Will Power, Scott Dixon (3) |
| Most Wins Team: | Team Penske (7) |
| Most Wins Manufacturer: | Chassis: Dallara (14) Engine: Honda (8) |
The IndyCar Grand Prix of Sonoma was an IndyCar Series race held at Sonoma Raceway in Sonoma, California. The USAC Championship Car circuit raced at the circuit in 1970. In 2005, American open wheel racing returned to the circuit with an IndyCar Series event. The 2006 event saw rookie Marco Andretti win his first career race. It marked the record youngest winner (19 years, 5 months, 14 days) of a major open-wheel racing event at the time.
The IndyCar Series race utilizes a modified 2.2miles version of the road course, the same used by AMA Superbike. The circuit includes the carousel, making it longer than the NASCAR layout, but shorter than the full 2.52miles course. This course uses turn 7a of the NASCAR course, but skips the hairpin prior to the front straight. The dragstrip is used instead of the keyhole, adding a high speed section immediately following the exit of the carousel.
For 2012, the course was altered. The back hairpin used the inner loop instead of the outer loop used by NASCAR. Turn nine was widened by ten feet while turn eleven at the hairpin was extended by 200 feet.
From 2015 to 2018, the race had served as the IndyCar season finale.
It was announced on July 13, 2018, that the Monterey Grand Prix at WeatherTech Raceway Laguna Seca would replace Sonoma for the 2019 IndyCar Series season.[1]
| Season | Date | Driver | Team | Chassis | Engine | Race Distance | Race Time | Average Speed (mph) | Report | |
|---|---|---|---|---|---|---|---|---|---|---|
| Laps | Miles (km) | |||||||||
| USAC Championship Car history | ||||||||||
| 1970 | April 4 |  Dan Gurney | All American Racers | Eagle | Ford | 60 | 151.2 (243.332) | 1:44:26 | 87.009 | Report |
| 1971 – 2004 | Not held | |||||||||
| IRL IndyCar Series history | ||||||||||
| 2005 | August 28 |  Tony Kanaan | Andretti Green Racing | Dallara | Honda | 80 | 159.2 (256.207) | 2:01:16 | 91.04 | Report |
| 2006 | August 27 | Marco Andretti | Andretti Green Racing | Dallara | Honda | 80 | 159.2 (256.207) | 1:58:06 | 93.486 | Report |
| 2007 | August 26 |  Scott Dixon | Chip Ganassi Racing | Dallara | Honda | 80 | 159.2 (256.207) | 1:51:59 | 98.593 | Report |
| 2008 | August 24 | Hélio Castroneves | Penske Racing | Dallara | Honda | 80 | 159.2 (256.207) | 1:50:16 | 100.254 | Report |
| 2009 | August 23 |  Dario Franchitti | Chip Ganassi Racing | Dallara | Honda | 75 | 166.5 (267.955) | 1:49:23 | 94.745 | Report |
| 2010 | August 22 |  Will Power | Team Penske | Dallara | Honda | 75 | 166.5 (267.955) | 1:52:34 | 92.063 | Report |
| 2011 | August 28 | Will Power | Team Penske | Dallara | Honda | 75 | 166.5 (267.955) | 1:47:30 | 96.408 | Report |
| 2012 | August 26 | Ryan Briscoe | Team Penske | Dallara | Chevrolet | 85 | 195.755 (315.037) | 2:07:03 | 95.74 | Report |
| 2013 | August 25 | Will Power | Team Penske | Dallara | Chevrolet | 85 | 195.755 (315.037) | 2:20:47 | 86.401 | Report |
| 2014 | August 24 | Scott Dixon | Chip Ganassi Racing | Dallara | Chevrolet | 85 | 195.755 (315.037) | 2:09:21 | 94.026 | Report |
| 2015 | August 30 | Scott Dixon | Chip Ganassi Racing | Dallara | Chevrolet | 85 | 195.755 (315.037) | 2:09:14 | 94.117 | Report |
| 2016 | September 18 |  Simon Pagenaud | Team Penske | Dallara | Chevrolet | 85 | 195.755 (315.037) | 2:00:13 | 101.181 | Report |
| 2017 | September 17 | Simon Pagenaud | Team Penske | Dallara | Chevrolet | 85 | 202.725 (326.254) | 1:55:53 | 104.968 | Report |
| 2018 | September 16 | Ryan Hunter-Reay | Andretti Autosport | Dallara | Honda | 85 | 202.725 (326.254) | 2:02:19 | 99.44 | Report |
| [2] | ||||||||||