The Peak Antifreeze and Motor Oil Indy 300 was an IndyCar Series race held at Chicagoland Speedway in Joliet, Illinois, United States. In 2001, American open wheel racing debuted at the circuit with an IndyCar Series event. From 2006 to 2008, the race had served as the final round of the championship and where the series champion was decided. Indy/Championship car racing first appeared in the Chicago area in 1914–1915 at Galesburg District Fairgrounds. Both races were 100 laps around the 1 mi dirt oval. AAA held races at Speedway Park, a 2 mi board track in nearby Maywood, Illinois. The first such race was a 500 mi event in 1915. Subsequent races ranged from 10–300 miles, and the final race was held in 1918. The track was eventually demolished, and the Edward Hines Veterans Hospital now stands on its former location. Although no races would be held in the Chicago area until 1999, the state of Illinois hosted numerous USAC Championship Car races at Springfield and DuQuoin. A CART race known as the Grand Prix of Chicago was held at Chicago Motor Speedway in Cicero, just outside Chicago, from 1999 to 2002. It was discontinued, however, when the track closed after the 2002 race. Chicagoland Speedway gained a reputation as one of the most competitive oval circuits in the IRL with many races featuring extremely tight racing and close finishes, most notably 2002, 2003, 2008, and 2009. No car was able to break from the pack with most of the field usually running together and the leaders often directly nose to nose, similar to racing in NASCAR restrictor plate racing.

Notable races

Past winners

AAA Championship Car history (Galesburg)

AAA Championship Car history (Speedway Park)

Non-championship event

IndyCar Series history (Chicagoland)

Support Series

Indy Pro Series/Indy Lights

ARCA Menards Series

From 2001 to 2010 the ARCA Menards Series would run a race in support of the IndyCar series race.

NASCAR Gander RV & Outdoors Truck Series

In 2009 and 2010 the NASCAR Gander RV & Outdoors Truck Series ran a support race with the IndyCar weekend.