1987 Indianapolis 500 Al Unser, Sr. held off Roberto Guerrero by 4.496 seconds, to win his record-tying fourth Indianapolis 500 victory. By leading the final 18 laps, Unser, Sr. tied the all-time record for most laps led in Indy 500 competition, and, at 47 years of age, also became the oldest winner of the 500. Mario Andretti's dominance of the month, and subsequent failure to achieve victory, was largely unprecedented in modern times. He led the practice speed chart on 11 of the 17 days (he participated in only 13 days), won the pole position, won the pit stop contest, had the fastest
1997 Indianapolis 500 sanctioning the IRL and Indy 500, in favor of in-house officiating. The win by Arie Luyendyk marked the milestone 50th Indianapolis 500 victory for Firestone. It was Luyendyk's second Indy victory (he also won in 1990), as well as Scott Goodyear's second runner-up finish (1992). It was the third time in his career that Goodyear narrowly lost the Indy 500 in the closing stages. Luyendyk became the first driver since A. J. Foyt to win the race with both a turbocharged and a normally-aspirated engine. The 1997 race utilized the traditional three week / four weekend schedule that had been