1968 (Champion: Lou Sell)
1. Continental Divide (USA), May 26-Lou Sell (USA)-Eagle Mk5-Chevrolet
2. War Bonnet (USA), Jun 16-Lou Sell (USA)-Eagle Mk5-Chevrolet
3. Road America (USA), Jul 27-Jerry Hansen (USA)-Lola T140-Chevrolet
4. Thompson (USA), Aug 18-Lou Sell (USA)-Eagle Mk5-Chevrolet
5. Mosport (CDN), Aug 25-Lou Sell (USA)-Eagle Mk5-Chevrolet
6. Lime Rock (USA), Sep 2-George Wintersteen (USA)-Eagle Mk5-Chevrolet
7. Brainerd (USA), Sep 22-George Wintersteen (USA)-Eagle Mk5-Chevrolet
8. Laguna Seca (USA), Oct 12-Lou Sell (USA)-Eagle Mk5-Chevrolet
1969 (Champion: Tony Adamowicz)
1. Riverside (USA), Apr 20-John Cannon (USA)-Eagle Mk5-Chevrolet
2. Laguna Seca (USA), May 4-Sam Posey (USA)-Eagle Mk5-Chevrolet
3. Continental Divide (USA), Jun 8-Dick Simon (USA)-Lola T142-Chevrolet
4. Sears Point (USA), Jun 22-John Cannon (USA)-Eagle Mk5-Chevrolet
5. Seattle (USA), Jul 6-Tony Adamowicz (USA)-Eagle Mk5-Chevrolet
6. Road America (USA), Jul 20-Tony Adamowicz (USA)-Eagle Mk5-Chevrolet
7. Lime Rock (USA), Aug 2-Peter Gethin (GB)-McLaren M10A-Chevrolet
8. Brainerd (USA), Aug 10-David Hobbs (GB)-Surtees TS5-Chevrolet
9. Mosport (CDN), Aug 23-John Cannon (USA)-Eagle Mk5-Chevrolet
10. Lime Rock (USA), Sep 1-Sam Posey (USA)-McLaren M10A-Chevrolet
11. St Jovite (CDN), Sep 7-David Hobbs (GB)-Surtees TS5-Chevrolet
12. Thompson (USA), Sep 21-David Hobbs (GB)-Surtees TS5-Chevrolet
13. Sebring (USA), Dec 28-David Hobbs (GB)-Surtees TS5-Chevrolet
1970 (Champion: John Cannon)
1. Riverside (USA), Apr 19-John Cannon (USA)-McLaren M10B-Chevrolet
2. Edmonton (CDN), May 24-Ron Grable (USA)-Lola T190-Chevrolet
3. Seattle (USA), Jun 7-John Cannon (USA)-McLaren M10B-Chevrolet
4. Laguna Seca (USA), Jun 14-Ron Grable (USA)-Lola T190-Chevrolet
5. Sears Point (USA), Jun 28-Gus Hutchison (USA)-Brabham BT26A-Cosworth
6. Dallas (USA), Jul 5-Gus Hutchison (USA)-Brabham BT26A-Cosworth
7. Road America (USA), Jul 18-John Cannon (USA)-McLaren M10B-Chevrolet
8. Mont Tremblant (CDN), Aug 1-George Follmer (USA)-Lotus 70-Ford
9. Brainerd (USA), Aug 16-David Hobbs (GB)-Surtees TS5A-Chevrolet
10. Lime Rock (USA), Sep 7-David Hobbs (GB)-Surtees TS5A-Chevrolet
11. Mosport (CDN), Sep 13-Mark Donohue (USA)-Lola T192-Chevrolet
12. Mid-Ohio (USA), Sep 27-George Follmer (USA)-Lotus 70-Ford
13. Sebring (USA), Oct 15-Mark Donohue (USA)-Lola T192-Chevrolet
1971 (Champion: David Hobbs)
1. Riverside (USA), Apr 25-Frank Matich (AUS)-McLaren M10B-Repco
2. Laguna Seca (USA), May 2-David Hobbs (GB)-Surtees TS5A-Chevrolet
3. Seattle (USA), May 23-David Hobbs (GB)-Surtees TS5A-Chevrolet
4. Mid-Ohio (USA), Jul 5-Sam Posey (USA)-Surtees TS8-Chevrolet
5. Road America (USA), Jul 18-David Hobbs (GB)-Surtees TS5A-Chevrolet
6. Edmonton (CDN), Aug 1-David Hobbs (GB)-Surtees TS5A-Chevrolet
7. Brainerd (USA), Aug 15-Brett Lunger (USA)-Lola T192-Chevrolet
8. Lime Rock (USA), Sep 6-David Hobbs (GB)-Surtees TS5A-Chevrolet
1972 (Champion: Graham McRae)
1. Laguna Seca (USA), May 7-Graham McRae (NZ)-Leda GM1-Chevrolet
2. Edmonton (CDN), Jun 4-David Hobbs (GB)-Lola T300-Chevrolet
3. Watkins Glen (USA), Jun 18-Graham McRae (NZ)-Leda GM1-Chevrolet
4. Road America (USA), Jul 16-Graham McRae (NZ)-Leda GM1-Chevrolet
5. Brainerd (USA), Jul 29-Eppie Wietzes (CDN)-Lola T300-Chevrolet
6. Road Atlanta (USA), Aug 20-Brett Lunger (USA)-Lola T300-Chevrolet
7. Lime Rock (USA), Sep 4-Brett Lunger (USA)-Lola T300-Chevrolet
8. Riverside (USA), Sep 24-Brian Redman (GB)-Chevron B24-Chevrolet
1973 (Champion: Jody Scheckter)
1. Riverside (USA), Apr 29-Brian Redman (GB)-Lola T330-Chevrolet
2. Laguna Seca (USA), May 6-Jody Scheckter (ZA)-Trojan T101-Chevrolet
3. Michigan (USA), May 20-Jody Scheckter (ZA)-Trojan T101-Chevrolet
4. Mid-Ohio (USA), Jun 3-Jody Scheckter (ZA)-Trojan T101-Chevrolet
5. Watkins Glen (USA), Jun 17-Jody Scheckter (ZA)-Lola T330-Chevrolet
6. Road America (USA), Jul 29-Brian Redman (GB)-Lola T330-Chevrolet
7. Road Atlanta (USA), Aug 19-Brian Redman (GB)-Lola T330-Chevrolet
8. Pocono (USA), Sep 3-Brian Redman (GB)-Lola T330-Chevrolet
9. Seattle (USA), Sep 30-Brian Redman (GB)-Lola T330-Chevrolet
1974 (Champion: Brian Redman)
1. Mid-Ohio (USA), Jun 2-Brian Redman (GB)-Lola T332-Chevrolet
2. Mosport (CDN), Jun 15-David Hobbs (GB)-Lola T332-Chevrolet
3. Watkins Glen (USA), Jul 14-Mario Andretti (USA)-Lola T332-Chevrolet
4. Road America (USA), Jul 28-Mario Andretti (USA)-Lola T332-Chevrolet
5. Ontario (CDN), Sep 1-Brian Redman (GB)-Lola T332-Chevrolet
6. Laguna Seca (USA), Oct 13-Brian Redman (GB) Lola T332-Chevrolet
7. Riverside (USA), Oct 27-Mario Andretti (USA) Lola T332-Chevrolet
1975 (Champion: Brian Redman)
1. Pocono (USA), Jun 1-Brian Redman (GB)-Lola T332-Chevrolet
2. Mosport (CDN), Jun 15-Mario Andretti (USA)-Lola T332-Chevrolet
3. Watkins Glen (USA), Jul 13-Brian Redman (GB)-Lola T332-Chevrolet
4. Road America (USA), Jul 27-Mario Andretti (USA)-Lola T332-Chevrolet
5. Mid-Ohio (USA), Aug 10-Brian Redman (GB)-Lola T332-Chevrolet
6. Road Atlanta (USA), Aug 31-Al Unser (USA)-Lola T332-Chevrolet
7. Long Beach (USA), Sep 28-Brian Redman (GB)-Lola T332-Chevrolet
8. Laguna Seca (USA), Oct 12-Mario Andretti (USA)-Lola T332-Chevrolet
9. Riverside (USA), Oct 26-Mario Andretti (USA)-Lola T332-Chevrolet
1976 (Champion: Brian Redman)
1. Pocono (USA), May 9-Brian Redman (GB)-Lola T332C-Chevrolet
2. Mosport (CDN), Jun 20-Alan Jones (AUS)-Lola T332-Chevrolet
3. Watkins Glen (USA), Jul 11-Alan Jones (AUS)-March 76A-Chevrolet
4. Road America (USA), Jul 25-Jackie Oliver (GB)-Shadow DN6B-Dodge
5. Mid-Ohio (USA), Aug 8-Brian Redman (GB)-Lola T332C-Chevrolet
6. Road America (USA), Aug 28-Brian Redman (GB)-Lola T332C-Chevrolet
7. Riverside (USA), Oct 17-Al Unser (USA)-Lola T332-Chevrolet
Total races: 82
Winning drivers
16 wins-Brian Redman
13 wins-David Hobbs
7 wins-Mario Andretti
6 wins-John Cannon
5 wins-Lou Sell
4 wins-Jody Scheckter
3 wins-Brett Lunger, Graham McRae, Sam Posey
2 wins-Tony Adamowicz, Mark Donohue, George Follmer, Ron Grable, Gus Hutchison, Alan Jones, Al Unser, George Wintersteen
1 win-Peter Gethin, Jerry Hansen, Frank Matich, Jackie Oliver, Dick Simon, Eppie Wietzes
Total winning drivers: 23
Winning nationalities
Australia-2 drivers (Jones, Matich)
Canada-1 driver (Wietzes)
Great Britain-4 drivers (Gethin, Hobbs, Oliver, Redman)
New Zealand-1 driver (McRae)
South Africa-1 driver (Scheckter)
United States-1 driver (Adamowicz, Andretti, Cannon, Donohue, Follmer, Grable, Hansen, Hutchison, Lunger, Posey, Sell, Simon, Unser, Wintersteen)
Total winning nationalities: 6
Winning manufacturers
38 wins-Lola
13 wins-Eagle
12 wins-Surtees
6 wins-McLaren
3 wins-Leda, Trojan
2 wins-Babham, Lotus
1 win-Chevron, March, Shadow
Total wins: 82 by 11 manufacturers
Winning engines
76 wins-Chevrolet
2 wins-Cosworth, Ford
1 win-Dodge, Repco
Total wins: 82 by 5 engine manufacturers