Hoosier Grand Prix
Indianapolis Raceway Park
1.875 Mile Road Course
80 Laps/150 Miles
July 24, 1966
| Finish | Start | Driver | Car # | Sponsor/Name | Chassis | Engine | Laps | Status |
Points |
| 1 | 2 | Mario Andretti | 1 | Dean Van Lines | Brawner Hawk | Ford | 80 | 1:34:22 95.373 | 300 |
| 2 | 7 | Al Unser | 24 | American Red Ball | Lola | Ford | 80 | Finished | 240 |
| 3 | 3 | Jim McElreath | 3 | Zink-Urschel-Slick | Brabham | Ford | 80 | Finished | 210 |
| 4 | 8 | Bobby Unser | 86 | Leader Card | Watson | Offy | 79 | Flagged | 180 |
| 5 | 4 | Gordon Johncock | 72 | Weinberger Homes | Gerhardt | Ford | 79 | Flagged | 150 |
| 6 | 14 | George Snider | 2 | Sheraton-Thompson | Coyote | Ford | 79 | Flagged | 15 |
| 7 | 10 | Ronnie Duman | 96 | Harrison | Eisert | Chevy | 79 | Flagged | 90 |
| 8 | 5 | Joe Leonard | 6 | Yamaha | Eagle | Ford | 79 | Flagged | 75 |
| 9 | 15 | Don Branson | 4 | Leader Card | Gerhardt | Ford | 79 | Flagged | 60 |
| 10 | 17 | Dick Atkins | 98 | Agajanian REV 500 | Shrike | Offy | 78 | Flagged | 45 |
| 11 | 22 | Sam Sessions | 40 | Federal Engineering | Trevis FE | Offy | 78 | Flagged | 30 |
| 12 | 18 | Bobby Grim | 39 | Racing Associates | Watson FE | Offy | 77 | Flagged | 15 |
| 13 | 12 | Billy Foster | 27 | Jim Robbins | Vollstedt | Ford | 76 | Flagged | |
| 14 | 23 | Bob Harkey | 81 | Central Excavating | Gerhardt | Offy | 75 | Flagged | |
| 15 | 20 | Al Miller (Krulac) | 85 | Caves Buick | Gerhardt | Offy SC | 65 | Flagged | |
| 16 | 1 | Lloyd Ruby | 29 | All American Racers | Lotus | Ford | 43 | Spun out | |
| 17 | 16 | Bud Tingelstad | 22 | Federal Engineering | Gerhardt | Offy SC | 42 | Spun out | |
| 18 | 9 | Chuck Hulse | 12 | Wynn's | Watson | Ford | 38 | Spun out | |
| 19 | 11 | Carl Williams | 77 | Dayton Steel Wheel | Gerhardt | Ford | 35 | Out | |
| 20 | 19 | Gary Congdon | 53 | Valvoline | Huffaker | Offy | 28 | Broken suspension | |
| 21 | 21 | Arnie Knepper | 37 | DVS | Cecil | Ford | 15 | Lost oil pressure | |
| 22 | 6 | Roger McCluskey | 8 | G. C. Murphy | Eagle | Ford | 12 | Fuel leak | |
| 23 | 24 | Johnny Boyd | 41 | Prestone | BRP | Ford | 8 | Lost oil pressure | |
| 24 | 13 | A. J. Foyt | 82 | Sheraton-Thompson | Lotus | Ford | 5 | Ignition | |
| -- | -- | A. J. Foyt | 2 | Sheraton-Thompson | Lotus | Ford | 69 | Relieved Snider 11-79 | 105 |
| -- | -- | Gary Bettenhausen | 61 | McManus Bros. | Meskowski D | Offy | -- | DNS, too slow | |
| -- | -- | Larry Dickson | 11 | Vita Fresh Orange Juice | Huffaker | Offy | -- | Wrecked practice | |
| -- | -- | Skip Hedrich | 84 | Foutch | Kurtis FE | Offy | -- | DNS, too slow | |
| -- | -- | Ralph Liguori | 35 | Flynn | Flynn | Offy | -- | DNS, too slow | |
| -- | -- | Cale Yarborough | 66 | Jim Robbins | Vollstedt | Ford | -- | Wrecked practice | |
| -- | -- | Art Pollard | 76 | GCR | Gerhardt | Offy SC | -- | DNS, too slow | |
| -- | -- | Al Smith | 71 | Fairchild-Hiller | Halibrand | Offy | -- | DNS, too slow | |
| -- | -- | Larry Dickson | 34 | Michner Petroleum | Lola | Ford | -- | Did not appear | |
| -- | -- | Bob King | 36 | Stahl Brothers | X | Chevy | -- | Did not appear | |
| -- | -- | Bobby Unser | 43 | Bowes Seal Fast | Lola | Ford | -- | Did not appear | |
| -- | -- | Bob Pratt | 70 | Smith Speed Shop | X | Chevy | -- | Did not appear | |
| -- | -- | Ray Duckworth | 97 | Stoye Racing | Stoye D | Offy | -- | Did not appear | |
| -- | -- | Bruce Jacobi | X | X | X | X | -- | Did not appear |
| Lap Leaders | Total | Laps |
| Mario Andretti | 38 | 43-80 |
| Jim McElreath | 18 | 1-6, 23-26, 35-42 |
| Al Unser | 10 | 13-14, 27-34 |
| Gordon Johncock | 8 | 15-22 |
| Roger McCluskey | 6 | 7-12 |