Following the tragic 1964 race, this race was run relatively clean with no major incidents. Contrary to some popular belief, gasoline was not banned for the 1965 race. Instead, USAC officials cleverly crafted several rule changes that effectively encouraged teams to use methanol in order to be competitive.
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 flanks 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 feed, a rule that still is in effect as of 2017.
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.
In addition to the changes to fueling procedures, a new minimum weight of 1,250 pounds was also established.The 500 Festival Open Invitation was held May 24–27.
After suffering a terrible crash in January at the Motor Trend 500 at Riverside, A. J. Foyt was back behind the wheel in time for the 500. Foyt had suffered a broken back, crushed sternum, and a concussion after he lost his brakes, hit an embankment, and flipped violently in a stock car.
There would be considerable turnaround in the starting lineup, with eleven rookies making the race, the most since 1951 (12). The rookie class of 1965 was historically notable, including such drivers as Mario Andretti, Al Unser, Sr., Gordon Johncock, Joe Leonard, and George Snider.
The track opened for practice on Saturday May 1. On Monday May 3, Jim Clark turned a lap of 150.779 mph, the first driver over 150 mph for the month. On Tuesday May 4, chief steward Harlan Fengler lifts the speed limits, and A. J. Foyt ups his practice speed to 155 mph.
On Wednesday May 5, A. J. Foyt's Lotus-Ford wrecked on the backstretch when a magnesium hub carrier snapped. The next day, all of the Lotus-Fords and Lola cars were parked by USAC for a few days until the tests and improvements could be made to the magnesium parts. Thursday's practice was cut short due to rain.
On Monday May 10, after adequate improvements, the Lotus-Fords were authorized to return to the track. Both Foyt and Clark turned laps over 158 mph. Foyt and Clark continued to top the speed charts during the week, and on Thursday, Foyt blistered the track with a new unofficial track record of 161.146 mph.
On the day before pole day, Ebb Rose spun in turn one in front of Bobby Unser, collecting him in the crash. Unser was driving the brand new four-wheel drive Novi car entered by Andy Granatelli. Unser's car t-boned Rose's car, and spun wildly into the outside wall. Rose was not hurt. Unser was sent to the hospital for x-rays, but was not seriously injured.
Pole day was a record-setting, historic day, as drivers officially broke the 160 mph barrier. Mario Andretti was one of the first drivers to set the pace, putting in a lap of 159.406 mph, and a four-lap average of 158.849 mph. Later, Jim Clark in the Lotus 38, became the first driver to break the 160 mph barrier. His first two laps of 160.772 mph and 160.973 mph set one-lap records. His record four-lap average of 160.729 mph tentatively put himself on the pole.
Defending race winner A. J. Foyt ended up as the fastest of the day, with three laps in the 161 mph range. His first lap of 161.958 mph established the new one-lap track record. His record four-lap average of 161.233 secured the pole position, his first such pole at Indy.
A day after his crash during practice, Bobby Unser got in a year-old Novi back up car to qualify 8th. Nineteen cars qualified on pole day.
Strong winds kept most cars off the track. Only two cars (Don Branson and Arnie Knepper) qualified. At the end of the first weekend of time trials, the field was filled to 21 cars.
Jim Hurtubise, who was seriously burned in a crash at Milwaukee in 1964, completed his comeback by qualifying one of the Novi machines at 156.860 mph. He was the fastest of the day, which saw 11 cars complete qualifying runs.
Two cars crashed during the day, Rodger Ward and Lloyd Ruby. Ruby wrecked his already-qualified machine, but Ward was still struggling to get up to speed. Masten Gregory and Al Unser both blew engines, but were able to keep the cars off the wall.
Bobby Johns, a NASCAR regular, skipped the World 600 Charlotte, and entered as a teammate to Jim Clark in another Lotus machine. He qualified for 22nd position, third fastest of the afternoon.
At the end of the day, there was only one spot left open in the field.
Former winner Rodger Ward failed to qualify. He suffered a crash and three blown engines during the month. He got onto the track in the final 15 minutes, but his qualifying attempt was too slow to make the field.
Bob Mathouser was the final driver in Indy history to attempt to qualify in a front-wheel drive machine, but the engine blew and he did not make the field.
The Wood Brothers from the NASCAR Grand National circuit, were invited by Ford Motor Company to work the pit stops for Team Lotus (drivers Jim Clark and Bobby Johns). Their arrival at the Speedway was quickly recognized and much reported. They were well known for their rapid pit stop work in NASCAR, and their presence immediately created a stir in the garage area. It took them only a short time to acclimate themselves to the open wheel championship cars' equipment.
Their contributions to the victory, however, have been considered overstated by media and others alike. Historians agree that Clark's Lotus-Ford was capable of winning the race handily with or without the added help of the Wood Brothers. In fact, the only work done on the cars was routine refueling, as they did not need to change tires during the race. Clark made only two stops all day, and the quickness of the refueling process was largely attributed to a specially-designed gravity fueling rig with a venturi tube. One of the things they did do ahead of time was to "break in" the new fueling hose nozzles by simply working them in and out of the coupling for a period of time.
A. J. Foyt started on the pole, but Jim Clark led the first lap. Jim Hurtubise dropped out with a broken transmission on the first lap. Foyt took the lead on lap two, and at first glance, the early laps appeared as if they were going to develop into a duel. However, Clark re-took the lead on lap 3, and pulled away.
Heavy attrition saw 17 cars drop out with engine or mechanical trouble before reaching the halfway point.
Lloyd Ruby spun, but was able to continue. He went to the pits for new tires, but the heavily flat-spotted tires required a minute and a half to change.
Clark led until lap 65, giving up the lead for a pit stop. A. J. Foyt led from lap 66-74. On lap 75, Clark regained the lead of the race.
Jim Clark still led at the halfway point, and would not relinquish the lead for the remainder of the race. Early contender A. J. Foyt dropped out after 115 laps with a broken gearbox.
The lone accident of the day involved Bud Tingelstad, who lost a wheel and spun into the outside wall in turn three.
Scotland's Jim Clark became the first non-American winner of the Indianapolis 500 since 1916. Clark led three times for a total of 190 laps. Only eleven cars were running at the finish. Second place Parnelli Jones ran out of fuel on the final lap, and pushed his car back to the pits.
Rookie Mario Andretti, who ran no lower than 6th all afternoon, came home third, and won the Rookie of the Year award. Despite rapidly becoming obsolete, two front-engined roadsters still finished in the top ten. Rookie Gordon Johncock finished 5th, and Eddie Johnson came home 10th. Johncock was locked in a duel with Al Miller in the late stages of the race.
The race was slowed by only three yellow lights for a total of 13 minutes.First alternate: Rodger Ward (#2)
The race was carried live on the IMS Radio Network. Sid Collins served as chief announcer for the 14th year, and 18th year overall with the crew. Fred Agabashian served as "driver expert," and Rodger Ward (who failed to qualify), joined the pre-race coverage briefly to offer commentary. The four and a half hour broadcast opened with a 30-minute pre-race segment.
The broadcast was carried by over 800 affiliates and was heard by an estimated 100 million listeners worldwide. The broadcast was carried by Armed Forces Network, as well as Radio New York Worldwide. Foreign translation rebroadcasts in Spanish, Portuguese, French, and Italian were heard in Central and South America and elsewhere.
After visiting the broadcast booth in 1964 for an interview, Donald Davidson returned, joining the crew full-time as race historian. Also new for 1965 was Ron Carrell, who reported from the backstretch. Other guests that visited the booth included Gus Grissom, Senator Birch Bayh, Assistant Postmaster General Tyler Able, Wally Parks, Peter DePaolo, J. C. Agajanian, 500 Festival Chairperson Margaret Clark and 500 Festival Queen Suzanne Devine Sams.
Charlie Brockman, who had served on the broadcast crew since 1952, left to anchor the MCA closed-circuit television telecasts. Also absent from the crew was nine-year veteran Jack Shapiro, who died the previous summer at the age of 37.
The race was carried in the United States on ABC's Wide World of Sports. The broadcast aired on Saturday June 5. Charlie Brockman anchored the telecast, ABC's first coverage of Indy on race day. The telecast was an edited tape of a broadcast aired live on MCA closed-circuit television in various theaters across the United States. Charlie Brockman served as anchor and analyst was Rodger Ward for both the closed-circuit broadcast and the edited version aired the next week on ABC. Ward sat out the 1965 race, but returned in 1966.