1991 Indianapolis 500

The 75th Indianapolis 500 was held at the Indianapolis Motor Speedway in Speedway, Indiana, on Sunday, May 26, 1991. Rick Mears won from the pole position, becoming the third four-time winner of the Indy 500, joining A. J. Foyt and Al Unser. During time trials, Mears also established an Indy record by winning his sixth career pole position. The month of May for Mears was tumultuous, as he suffered his first ever crash at Indy since arriving as a rookie in 1977. The wreck during a practice run totaled his primary car, and broke a bone in his right foot. Mears kept the injury mostly secret, and later admitted that the pain he experienced during the race was so bad, he had to cross his legs in the car and push the accelerator pedal down with his left foot.

The race was noteworthy in that it featured the first African American driver to qualify for the Indianapolis 500, Willy T. Ribbs. It also saw its first Japanese driver, Hiro Matsushita. The pre-race attention going into the month focused on A. J. Foyt, who announced that he would retire from driving after the end of the 1991 season. During time trials, Foyt qualified on the front row, his record 34th consecutive Indy 500 appearance. On race day, however, Foyt dropped out early due to suspension damage. He eventually retracted his retirement plans, and returned one final time in 1992.

During time trials, a sudden rain shower halted pole qualifying, unexpectedly shutting out several contenders from a chance at the front row. A number of top drivers were forced to qualify on the second day of time trials. Gary Bettenhausen in a Buick-powered machine was the surprise fastest qualifier, albeit he was ineligible for the pole position. For the first time in Indy history, four members of the same family qualified for the same race. Mario, Michael, Jeff, and John Andretti competed together. Michael, Mario, and John all finished in the top ten, while Jeff was named the Rookie of the Year. Michael Andretti led the most laps during the race and battled Rick Mears for the win in the closing stages. Andretti executed a daring pass for the lead on the outside of turn one on lap 187. Mears, however, made a similar pass one lap later to re-take the lead, and drove to victory. Michael's second-place finish would ultimately be his career best finish at Indy.

The race was sanctioned by USAC, and was included as part of the 1991 CART PPG Indy Car World Series. Morning rain delayed the start of the race by about 55 minutes. The rain stopped, the track was dried, and the race was run to completion without interruption. Later in the year, Rick Mears would also win the Michigan 500, sweeping both 500-mile races for the season, the final two victories of his racing career.

A. J. Foyt suffered a crash at Road America in September 1990, which seriously injured both his feet and legs. Foyt underwent rehabilitation during the offseason, supervised by Steve Watterson, the strength and rehabilitation coach for the Houston Oilers. Foyt announced in November 1990 that he would retire at the end of the 1991 season. Foyt was planning a part-time Indy car schedule for 1991, racing at some ovals and a few road courses, and the 1991 Indianapolis 500 would be his last start at Indy. Still unable to drive due to his recuperation, Foyt skipped the Daytona 500 in February, the first time that he missed that race since 1968. Foyt initially planned to race at Phoenix on April 21, but nevertheless took a very cautious approach to his return. He scheduled a private test at Indy on April 4–6, but had to cut the test short due to pain and other factors, and doctors refused to clear him to race. Al Unser filled in for Foyt at Phoenix. Bernard Jourdain and Mike Groff filled for Foyt at the other CART series races, with Jourdain running a second car at Indy. Foyt's comeback was finally complete when he took his first practice laps on Monday May 6.

Only a few team/driver changes occurred during the offseason, while most of the key fixtures from 1990 remained on the same respective teams. Among the handful of changes, Penske Racing reduced from a three-car team down to two cars. Danny Sullivan departed Penske, and joined the Pat Patrick Alfa Romeo effort. Rick Mears' familiar Pennzoil Z-7 Special livery was gone for 1991, as Marlboro sponsored both Penske team cars (Mears and Emerson Fittipaldi).

Doug Shierson Racing, who won the 1990 race with driver Arie Luyendyk, was sold to businessman Bob Tezak. The team was re-organized in a joint effort with Vince Granatelli, and re-booted as UNO/Granatelli Racing. The car's former sponsor Domino's Pizza left the sport, and the livery was changed to the classic day-glow orange utilized by Granatelli entries over the years. Luyendyk's services were retained for 1991 (he won earlier in the season at Phoenix), but the entry suffered from a lack of sponsorship. During most of the season, the car had blank sidepods, but RCA sponsored the entry at Indy.

John Andretti joined the newly rebooted Hall-VDS team, taking over the Pennzoil sponsorship. Andretti kicked off the season by winning his first (and only) career CART race at the season opener, the Gold Coast Grand Prix at Surfers Paradise.