The 49th International 500-Mile Sweepstakes was held at the Indianapolis Motor Speedway in Speedway, Indiana on Monday, May 31, 1965.
The five-year-old "British Invasion" finally broke through as Jim Clark and Colin Chapman triumphed in dominating fashion with the first rear-engined Indy-winning car, a Lotus 38 powered by Ford. With only six of the 33 cars in the field having front engines, it was the first 500 in history to have a majority of cars as rear-engined machines.
Clark, of Scotland, started from the front row, and led 190 laps, the most since Bill Vukovich (195) in 1953. He became the first non-American winner of the Indianapolis 500 since 1920 when Frenchman Gaston Chevrolet won. Clark would go on to win the 1965 World Championship (which Indianapolis was not part of any longer). He is the only driver in history to win the Indy 500 and Formula One World Championship in the same year. Clark actually chose to skip Monaco to compete at Indy.
ABC Sports covered the race for the first time on Wide World of Sports. Charlie Brockman anchored the broadcast along with Rodger Ward.
Rule changes
Following the tragic 1964 race, this race was run relatively clean with no major accidents. Contrary to some popular belief, gasoline was not banned for the 1965 race. Instead, USAC officials crafted several calculated rule changes to effectively encourage teams to use methanol in order to be competitive. In addition, a new minimum car weight of 1,250 pounds was also established.
For 1965, all cars were required to make a minimum of two pit stops. A pit stop was generally defined as coming to a complete stop in the respective pit box, and hooking up the fueling mechanism. Tire changes were not specifically required, and some cars in fact changed zero tires all day. On-board fuel tank capacity was reduced to 75 gallons, which also included requirements that they contain rubber bladders inside, and were required to be behind the driver on the left side of each car. Crossover tubes were no longer allowed ahead of the driver as well. Pressurized fueling rigs were also outlawed. All fueling rigs from 1965 onward had to be gravity fed, a rule that still is in effect as of 2023.
Conventional "pump" gasoline registered better fuel mileage than methanol, and could go a longer distance before needing to refuel. The methanol-powered engines had worse fuel mileage, but were expected to produce more horsepower and effectively race faster. Since cars were required to make a minimum of two fuel stops, the advantage to using gasoline (i.e., fewer pit stops and better resulting track position) was diminished, or outright lost.
While most teams switched to methanol, the Agajanian team decided to utilize a methanol/gasoline blend. Chief mechanic Johnny Pulson and driver Parnelli Jones determined that they were effectively down on power, finished second, and attributed the fuel blend as what cost them a chance to win the race.
Time trials
One other major change was implemented for time trials. The evening before pole day time trials, a new blind draw was to be used to establish the qualifying order (namely for Pole Day). Prior to 1965, no draw was used, and the qualifying order was a "first-come, first-served" line-up, queued down the pit lane and usually stretching into the garage area. Some teams would even claim their spots in line the night before. The unorganized scramble to roll the cars into a queue had often led to heated exchanges, collisions, and unfair situations.
Each entry would still be allowed up to three attempts to qualify (across all four scheduled days). Once the original qualifying draw order had been exhausted on Pole Day, if there was still time left in the day (prior to the traditional 6 o'clock gun), the track was open for qualifying on a first-come, first-served basis. A proposal to charge cars with an attempt if they got to the front of the line but elected not to go out, or went out and did not take the green flag to start the run, was rejected. Despite the addition of a qualifying draw, each car in the order was not yet guaranteed the opportunity to make an attempt during the pole round. If rain were to delay or interrupt the qualifying line on Pole Day, any cars left in the original qualifying order at the time the track closed (due to rain or at the 6 o'clock gun) were simply out of luck, and had to qualify on the next round. This technicality would be corrected in 1971.
Race schedule
The 500 Festival Open Invitation golf tournament was held May 24–27.