O Cadillac DP #5 da Mustang Sampling Racing de Filipe Albuquerque, Christian Fittipaldi e Gabby Chaves foi sétimo e décimo nas duas sessões de treinos livres para as 6 Horas de Watkins Glen, estando para já a cerca de um segundo dos mais rápidos. Na classe GTD, Álvaro Parente e Katherine Legge fora 14º e 6º na classe, no Acura NSX GT3 da Meyer Shank Racing.
| POS | # | TEAM | CLASS | VEHICLE | Piloto1 | Piloto2 | Piloto3 | TIME |
| 1 | 6 | Acura Team Penske | P | Acura DPi | Cameron | Montoya | 1:33.562 | |
| 2 | 10 | Konica Minolta Cadillac DPi-V.R | P | Cadillac DPi | Van Der Zande | Taylor | +0.914 | |
| 3 | 54 | CORE autosport | P | ORECA LMP2 | Bennett | Braun | Dumas | +0.928 |
| 4 | 2 | Tequila Patron ESM | P | Nissan DPi | Sharp | Dalziel | Pla | 1.075 |
| 5 | 90 | Spirit of Daytona Racing | P | Cadillac DPi | McMurry | Vautier | 1.087 | |
| 6 | 7 | Acura Team Penske | P | Acura DPi | Castroneves | Taylor | 1.409 | |
| 7 | 5 | Mustang Sampling Racing | P | Cadillac DPi | Albuquerque | Fittipaldi | Chaves | 1.444 |
| 8 | 99 | JDC-Miller Motorsports | P | ORECA LMP2 | Goikhberg | Simpson | Miller | 1.599 |
| 9 | 22 | Tequila Patron ESM | P | Nissan DPi | van Overbeek | Derani | Lapierre | 1.716 |
| 10 | 52 | AFS/PR1 Mathiasen Motorsports | P | Ligier LMP2 | Saavedra | Yacaman | Owen | 1.763 |
| 11 | 55 | Mazda Team Joest | P | Mazda DPi | Bomarito | Tincknell | Pigot | 1.802 |
| 12 | 31 | Whelen Engineering Racing | P | Cadillac DPi | Nasr | Curran | Conway | 1.807 |
| 13 | 32 | United Autosports | P | Ligier LMP2 | Hanson | Senna | Di Resta | 1.890 |
| 14 | 85 | JDC-Miller Motorsports | P | ORECA LMP2 | Trummer | Alon | Panciatici | 1.972 |
| 15 | 38 | Performance Tech Motorsports | P | ORECA LMP2 | French | Masson | Miller | 2.615 |
| 16 | 77 | Mazda Team Joest | P | Mazda DPi | Jarvis | Nunez | Rast | 2.800 |
| 17 | 67 | Ford Chip Ganassi Racing | GTLM | Ford GT | Briscoe | Westbrook | 9.652 | |
| 18 | 66 | Ford Chip Ganassi Racing | GTLM | Ford GT | Hand | Mueller | 9.858 | |
| 19 | 911 | Porsche GT Team | GTLM | Porsche 911 RSR | Tandy | Pilet | 9.950 | |
| 20 | 3 | Corvette Racing | GTLM | Chevrolet Corvette C7.R | Magnussen | Garcia | 9.997 | |
| 21 | 4 | Corvette Racing | GTLM | Chevrolet Corvette C7.R | Gavin | Milner | 10.136 | |
| 22 | 912 | Porsche GT Team | GTLM | Porsche 911 RSR | Vanthoor | Bamber | 10.452 | |
| 23 | 24 | BMW Team RLL | GTLM | BMW M8 GTE | Krohn | Edwards | Blomqvist | 11.180 |
| 24 | 15 | 3GT Racing | GTD | Lexus RC F GT3 | Hawksworth | Farnbacher | Heinemeier Hansson | 11.881 |
| 25 | 63 | Scuderia Corsa | GTD | Ferrari 488 GT3 | MacNeil | Jeannette | Segal | 12.051 |
| 26 | 51 | Squadra Corse Garage Italia | GTD | Ferrari 488 GT3 | Piovanetti | Negri | Serra | 12.206 |
| 27 | 25 | BMW Team RLL | GTLM | BMW M8 GTE | Sims | De Phillippi | Auberlen | 12.217 |
| 28 | 14 | 3GT Racing | GTD | Lexus RC F GT3 | Baumann | Marcelli | 12.223 | |
| 29 | 96 | Turner Motorsport | GTD | BMW M6 GT3 | Machavern | Palttala | Yount | 12.337 |
| 30 | 93 | Meyer Shank Racing w/ Curb-Agajanian | GTD | Acura NSX GT3 | Marks | Aschenbach | 12.365 | |
| 31 | 44 | Magnus Racing | GTD | Audi R8 LMS GT3 | Potter | Lally | Davis | 12.375 |
| 32 | 71 | P1 Motorsports | GTD | Mercedes-AMG GT3 | Perez | Spinelli | Morad | 12.396 |
| 33 | 33 | Mercedes-AMG Team Riley Motorsports | GTD | Mercedes-AMG GT3 | Keating | Bleekemolen | Stolz | 12.462 |
| 34 | 29 | Montaplast by Land-Motorsport | GTD | Audi R8 LMS GT3 | van der Linde | Mies | 12.964 | |
| 35 | 64 | Scuderia Corsa | GTD | Ferrari 488 GT3 | Sweedler | Bell | Montecalvo | 12.982 |
| 36 | 48 | Paul Miller Racing | GTD | Lamborghini Huracan GT3 | Sellers | Snow | 13.052 | |
| 37 | 73 | Park Place Motorsports | GTD | Porsche 911 GT3 R | Lindsey | Bergmeister | 13.172 | |
| 38 | 86 | Meyer Shank Racing w/ Curb-Agajanian | GTD | Acura NSX GT3 | Legge | Parente | 13.273 | |
| 39 | 75 | SunEnergy1 Racing | GTD | Mercedes-AMG GT3 | Habul | Jaeger | Grenier | 13.661 |
| 40 | 69 | HART | GTD | Acura NSX GT3 | Gilsinger | Eversley | Dyer | 14.090 |
| 41 | 58 | Wright Motorsports | GTD | Porsche 911 GT3 R | Long | Nielsen | Renauer | 14.438 |
| 42 | 36 | CJ Wilson Racing | GTD | Acura NSX GT3 | Miller | Bechtolsheimer | 14.873 | |
| POS | NUMBER | TEAM | CLASS | VEHICLE | Piloto1 | Piloto2 | Piloto3 | TIME |
| 1 | 54 | CORE autosport | P | ORECA LMP2 | Bennett | Braun | Dumas | 1:33.481 |
| 2 | 10 | Konica Minolta Cadillac DPi-V.R | P | Cadillac DPi | Van Der Zande | Taylor | +0.276 | |
| 3 | 6 | Acura Team Penske | P | Acura DPi | Cameron | Montoya | +0.346 | |
| 4 | 32 | United Autosports | P | Ligier LMP2 | Hanson | Senna | Di Resta | +0.602 |
| 5 | 7 | Acura Team Penske | P | Acura DPi | Castroneves | Taylor | +0.634 | |
| 6 | 90 | Spirit of Daytona Racing | P | Cadillac DPi | McMurry | Vautier | +0.647 | |
| 7 | 2 | Tequila Patron ESM | P | Nissan DPi | Sharp | Dalziel | Pla | +0.683 |
| 8 | 22 | Tequila Patron ESM | P | Nissan DPi | van Overbeek | Derani | Lapierre | +0.852 |
| 9 | 77 | Mazda Team Joest | P | Mazda DPi | Jarvis | Nunez | Rast | +0.869 |
| 10 | 5 | Mustang Sampling Racing | P | Cadillac DPi | Albuquerque | Fittipaldi | Chaves | 1.032 |
| 11 | 52 | AFS/PR1 Mathiasen Motorsports | P | Ligier LMP2 | Saavedra | Yacaman | Owen | 1.050 |
| 12 | 31 | Whelen Engineering Racing | P | Cadillac DPi | Nasr | Curran | Conway | 1.102 |
| 13 | 55 | Mazda Team Joest | P | Mazda DPi | Bomarito | Tincknell | Pigot | 1.243 |
| 14 | 99 | JDC-Miller Motorsports | P | ORECA LMP2 | Goikhberg | Simpson | Miller | 1.531 |
| 15 | 38 | Performance Tech Motorsports | P | ORECA LMP2 | French | Masson | Miller | 1.541 |
| 16 | 85 | JDC-Miller Motorsports | P | ORECA LMP2 | Trummer | Alon | Panciatici | 1.592 |
| 17 | 67 | Ford Chip Ganassi Racing | GTLM | Ford GT | Briscoe | Westbrook | 9.405 | |
| 18 | 66 | Ford Chip Ganassi Racing | GTLM | Ford GT | Hand | Mueller | 9.603 | |
| 19 | 912 | Porsche GT Team | GTLM | Porsche 911 RSR | Vanthoor | Bamber | 9.718 | |
| 20 | 911 | Porsche GT Team | GTLM | Porsche 911 RSR | Tandy | Pilet | 10.095 | |
| 21 | 3 | Corvette Racing | GTLM | Chevrolet Corvette C7.R | Magnussen | Garcia | 10.180 | |
| 22 | 4 | Corvette Racing | GTLM | Chevrolet Corvette C7.R | Gavin | Milner | 10.313 | |
| 23 | 24 | BMW Team RLL | GTLM | BMW M8 GTE | Krohn | Edwards | Blomqvist | 10.530 |
| 24 | 25 | BMW Team RLL | GTLM | BMW M8 GTE | Sims | De Phillippi | Auberlen | 11.661 |
| 25 | 29 | Montaplast by Land-Motorsport | GTD | Audi R8 LMS GT3 | van der Linde | Mies | 11.710 | |
| 26 | 14 | 3GT Racing | GTD | Lexus RC F GT3 | Baumann | Marcelli | 11.961 | |
| 27 | 51 | Squadra Corse Garage Italia | GTD | Ferrari 488 GT3 | Piovanetti | Negri | Serra | 12.011 |
| 28 | 63 | Scuderia Corsa | GTD | Ferrari 488 GT3 | MacNeil | Jeannette | Segal | 12.063 |
| 29 | 93 | Meyer Shank Racing w/ Curb-Agajanian | GTD | Acura NSX GT3 | Marks | Aschenbach | 12.267 | |
| 30 | 86 | Meyer Shank Racing w/ Curb-Agajanian | GTD | Acura NSX GT3 | Legge | Parente | 12.279 | |
| 31 | 33 | Mercedes-AMG Team Riley Motorsports | GTD | Mercedes-AMG GT3 | Keating | Bleekemolen | Stolz | 12.323 |
| 32 | 71 | P1 Motorsports | GTD | Mercedes-AMG GT3 | Perez | Spinelli | Morad | 12.499 |
| 33 | 44 | Magnus Racing | GTD | Audi R8 LMS GT3 | Potter | Lally | Davis | 12.600 |
| 34 | 96 | Turner Motorsport | GTD | BMW M6 GT3 | Machavern | Palttala | Yount | 12.635 |
| 35 | 73 | Park Place Motorsports | GTD | Porsche 911 GT3 R | Lindsey | Bergmeister | 12.707 | |
| 36 | 64 | Scuderia Corsa | GTD | Ferrari 488 GT3 | Sweedler | Bell | Montecalvo | 12.991 |
| 37 | 69 | HART | GTD | Acura NSX GT3 | Gilsinger | Eversley | Dyer | 13.009 |
| 38 | 48 | Paul Miller Racing | GTD | Lamborghini Huracan GT3 | Sellers | Snow | 13.063 | |
| 39 | 15 | 3GT Racing | GTD | Lexus RC F GT3 | Hawksworth | Farnbacher | Heinemeier Hansson | 13.090 |
| 40 | 75 | SunEnergy1 Racing | GTD | Mercedes-AMG GT3 | Habul | Jaeger | Grenier | 13.151 |
| 41 | 58 | Wright Motorsports | GTD | Porsche 911 GT3 R | Long | Nielsen | Renauer | 13.731 |
| 42 | 36 | CJ Wilson Racing | GTD | Acura NSX GT3 | Miller | Bechtolsheimer | 14.700 |
