Austin Dillon was fastest in opening practice at Las Vegas Motor Speedway. Dillon turned in a fastest lap of 29.951 in practice for the Monster Energy NASCAR Cup Series’ Pennzoil 400.
Practice Speeds MENCS Practice at LVMS
| RaceRank | No | Driver | BestLapTime | BestSpeed | BestLap | Laps |
| 1 | 3 | Austin Dillon | 29.951 | 180.294 | 8 | 11 |
| 2 | 8 | Daniel Hemric # | 29.987 | 180.078 | 5 | 11 |
| 3 | 11 | Denny Hamlin | 29.995 | 180.03 | 5 | 9 |
| 4 | 9 | Chase Elliott | 30.03 | 179.82 | 8 | 8 |
| 5 | 24 | William Byron | 30.047 | 179.718 | 10 | 10 |
| 6 | 10 | Aric Almirola | 30.088 | 179.474 | 8 | 8 |
| 7 | 18 | Kyle Busch | 30.104 | 179.378 | 5 | 8 |
| 8 | 43 | Bubba Wallace | 30.155 | 179.075 | 12 | 12 |
| 9 | 14 | Clint Bowyer | 30.163 | 179.027 | 6 | 10 |
| 10 | 37 | Chris Buescher | 30.163 | 179.027 | 11 | 11 |
| 11 | 95 | Matt DiBenedetto | 30.165 | 179.015 | 7 | 7 |
| 12 | 17 | Ricky Stenhouse Jr. | 30.219 | 178.696 | 10 | 10 |
| 13 | 47 | Ryan Preece # | 30.222 | 178.678 | 8 | 11 |
| 14 | 20 | Erik Jones | 30.224 | 178.666 | 5 | 7 |
| 15 | 4 | Kevin Harvick | 30.226 | 178.654 | 2 | 6 |
| 16 | 19 | Martin Truex Jr. | 30.231 | 178.625 | 5 | 8 |
| 17 | 12 | Ryan Blaney | 30.235 | 178.601 | 8 | 8 |
| 18 | 48 | Jimmie Johnson | 30.249 | 178.518 | 5 | 8 |
| 19 | 88 | Alex Bowman | 30.287 | 178.294 | 7 | 7 |
| 20 | 13 | Ty Dillon | 30.29 | 178.277 | 8 | 11 |
| 21 | 41 | Daniel Suarez | 30.296 | 178.241 | 2 | 8 |
| 22 | 2 | Brad Keselowski | 30.304 | 178.194 | 11 | 11 |
| 23 | 1 | Kurt Busch | 30.313 | 178.141 | 9 | 9 |
| 24 | 34 | Michael McDowell | 30.324 | 178.077 | 9 | 9 |
| 25 | 21 | Paul Menard | 30.331 | 178.036 | 5 | 10 |
| 26 | 42 | Kyle Larson | 30.331 | 178.036 | 7 | 10 |
| 27 | 22 | Joey Logano | 30.387 | 177.708 | 2 | 11 |
| 28 | 6 | Ryan Newman | 30.402 | 177.62 | 7 | 7 |
| 29 | *96 | Parker Kligerman(i) | 30.451 | 177.334 | 8 | 11 |
| 30 | 32 | Corey LaJoie | 30.537 | 176.835 | 8 | 8 |
| 31 | 38 | David Ragan | 30.631 | 176.292 | 5 | 8 |
| 32 | 36 | Matt Tifft # | 30.747 | 175.627 | 5 | 7 |
| 33 | 00 | Landon Cassill | 30.77 | 175.496 | 8 | 8 |
| 34 | 15 | Ross Chastain(i) | 31.132 | 173.455 | 2 | 2 |
| 35 | 51 | Cody Ware # | 31.32 | 172.414 | 8 | 10 |
| 36 | 52 | BJ McLeod(i) | 31.463 | 171.63 | 2 | 2 |
| 37 | 77 | Reed Sorenson | 31.757 | 170.041 | 4 | 4 |
| 38 | *66 | Joey Gase(i) | 32.318 | 167.09 | 7 | 15 |
