1990 Indianapolis 500

The 74th Indianapolis 500 was held at the Indianapolis Motor Speedway in Speedway, Indiana on Sunday, May 27, 1990. Dutchman Arie Luyendyk took the lead with 32 laps to go, and earned his first-ever victory in championship-level competition. It was the second consecutive year the Indy 500 was won by a foreign-born competitor, the first time that had occurred since 1965–1966. Luyendyk completed the 500 miles at an average speed of 185.981 mph (299.307 km/h), a record that stood for 23 years until 2013. In reference to the long-standing speed record, for many years the 1990 race was often referred to as "The Fastest 500".

Defending champion Emerson Fittipaldi started on the pole position and dominated the first half of the race. Setting a new track record in qualifying, Fittipaldi became the first driver to break the 225 mph barrier in time trials. Fittipaldi took the lead at the start, and led the first 92 laps, a new race record. He was looking to become the first back-to-back winner in nineteen years. In the second half of the race, however, he fell victim to blistering tires, fell a lap down, and wound up finishing third. Bobby Rahal, the 1986 winner, was in position to win his second Indy 500, but he too suffered handling problems, which dropped him to second at the finish. Luyendyk, driving for Doug Shierson Racing (the race would be Shierson's final 500), did not experience the handling issues that befell the other competitors, and won the race by a margin of 11.878 seconds.

A. J. Foyt, making his 33rd consecutive Indy start, finished in sixth place. Rookie Jeff Andretti attempted to become the unprecedented fourth member of the Andretti family to qualify for the same race, but was bumped on the final day of time trials. Jim Crawford survived a spectacular airborne crash during practice, and for the second year in a row, three-time winner Johnny Rutherford struggled to get his car up to speed, and failed to qualify.

Rain hampered much of the month, washing out nearly the entire first weekend of time trials as well as two practice days. The 1990 race was also the first Indy 500 presided over by Tony George, who was named president of the Speedway in January. The race was sanctioned by USAC, and was included as part of the 1990 CART PPG Indy Car World Series.

Controversy hovered over the month, regarding new aerodynamic rules. All teams utilizing 1989 (or older) model year chassis were required to affix a "diffuser" to the underbody ground effects tunnels, to reduce their depth by 2 inches – a rule intended to reduce downforce and curtail speeds. Teams that had the means to do so could also refabricate the entire undertray to conform to the new specifications. Competitors complained that the diffusers made their cars unstable and unbalanced, and were responsible for the increased number of practice crashes involving the older cars. Despite voiced complaints and meetings with officials, no changes were made to the rules. Ultimately, no major crashes occurred amongst the older cars during the race itself.

The Porsche Indycar team, led by Derrick Walker, was fresh off their first victory at Mid-Ohio in September 1989 with driver Teo Fabi. They planned to roll out a new March chassis for 1990, the first all-carbon fiber monocoque Indy car. Rules were evolving by the CART series (and likewise USAC) to eventually allow for all-carbon fiber chassis. Porsche interpreted the rules as permitting the car for 1990, provided they were granted a waiver, and embarked on the project. However, in January, the board of directors voted to disallow the chassis for competition in 1990. The Porsche team was forced to utilize a March chassis that was constructed with a then-standard aluminum bottom to adhere to the rules. All-carbon fiber monocoques would be delayed until 1991.

With the Pocono 500 disbanded after 1989, the 1990 Indy car season and beyond would no longer feature a "Triple crown" of 500-mile races. The triple crown would not return until 2013.

Team and driver changes for 1990 were highlighted by defending CART champion and defending Indy winner Emerson Fittipaldi (and sponsor Marlboro) departing Patrick Racing and joining Penske Racing. The Penske team would be a three-car effort in 1990 with Fittipaldi, Rick Mears, and Danny Sullivan.