More than 20 NASCAR drivers are primed and ready for arguably one of the most important tests in the sport's history this Thursday and Friday at Las Vegas Motor Speedway.

With NASCAR implementing a new aero package designed to reduce horsepower and foster tighter racing for all intermediate tracks' races, including the Pennzoil 400 presented by Jiffy Lube on March 3, race teams will be clamoring for data from drivers and engineers during the two-day session. The LVMS sessions will include drafting practice and will be the sport's first major litmus test heading into the 2019 season, and each lap will be scrutinized from every angle.

"It's almost at the very top (of all-time tests), obviously, because this is our one chance to work on communication and the new package, and we have some new players in the shop too, engineering-wise," said Matt McCall, who will be working as crew chief for Las Vegas' Kurt Busch for the first time at this week's test. "We've got a lot of different stuff we need to communicate on, not just between me and Kurt, but also the team and Kurt. So, it's pretty high up there, for sure."

Four past NASCAR Cup Series champions - seven-time champion Jimmie Johnson, 2015 champion Kyle Busch, 2012 champ Brad Keselowski and 2004 champ Kurt Busch - highlight a stable of 21 drivers who will be in town for the test, which is free to the public. Other locals returning to town for the test sessions are NASCAR Xfinity Series drivers Noah Gragson and Riley Herbst.

The test will mark the first track activity for Kurt Busch in the No. 1 Monster Energy Chevrolet for Chip Ganassi Racing, and he is excited to work out some kinks with McCall.

"For me, it's just to get behind the wheel and to feel the Chevrolet and feel the drivetrain and to go through a few setup changes," said Busch, who set his home track's speed record of 196.328 miles per hour in 2016. "But I think the most important thing is radio communication and how we want to mock-up certain pit stop sequences for changes as we're out on-track and just having that banter back and forth so when we roll into Daytona, we're best prepared. That's a big reason why Chip Ganassi Racing is having the No. 1 car go do this test is to work the bugs out of it and just work those sequences into how we're going to go attack things in Daytona."

This week's action also will be the first for Johnson with crew chief Kevin Meendering, as well as Ryan Newman's first seat time in the No. 6 Ford for Roush Fenway Racing.

The track activity will come just more than a month before the speedway's first NASCAR tripleheader weekend of the year, which will be preceded by two days of racing at the LVMS Dirt Track Feb. 27-28. The Strat 200 NASCAR Gander Outdoors Truck Series race and Strat Qualifying take place on Friday, March 1, with Saturday's racing action highlighted by the Boyd Gaming 300 NASCAR Xfinity Series race and the Pennzoil 400 presented by Jiffy Lube anchoring five consecutive days of racing at the nearly 1,000-acre facility with a 12:30 p.m. start on Sunday.

Various ticket packages, fun extras and special-access passes for LVMS's NASCAR weekends are available at or by calling 1-800-644-4444.

Driver list for NASCAR testing at LVMS

Monster Energy NASCAR Cup Series
0  Landon Cassill, Starcom Racing, Chevrolet
1  Kurt Busch, Chip Ganassi Racing, Chevrolet
2  Brad Keselowski, Team Penske, Ford
3  Austin Dillon, Richard Childress Racing, Chevrolet
6  Ryan Newman, Roush Fenway Racing, Ford
13  Ty Dillon, Germain Racing, Chevrolet
14  Clint Bowyer, Stewart-Haas Racing, Ford
18  Kyle Busch, Joe Gibbs Racing, Toyota
21  Paul Menard, Wood Brothers Racing, Ford
43  Bubba Wallace, Richard Petty Motorsports, Chevrolet
47  Ryan Preece, JTG Racing, Chevrolet
48  Jimmie Johnson, Hendrick Motorsports, Chevrolet
51  Cody Ware, Rick Ware Racing, Chevrolet
95  Matt DiBenedetto, Leavine Family Racing, Toyota
CWF  Ross Chastain, Chevrolet Racing
FWF  David Ragan, Ford Motor Company 
TWF  Drew Herring, Toyota Racing Development

NASCAR Xfinity Series
8  Zane Smith, JR Motorsports, Chevrolet
9  Noah Gragson, JR Motorsports, Chevrolet
18  Riley Herbst, Joe Gibbs Racing, Toyota
98  Chase Briscoe, Stewart-Haas Racing, Ford

Event schedule

Thursday, Jan. 31
8 a.m.--Practice begins; LVMS gates, grandstands and pit road (via infield tunnel) open to the public
11 a.m.--Drafting practice on track
Noon-1 p.m.--Driver's lunch break, driver group interviews in media center
3 p.m.--Drafting practice on track
5 p.m.--Drafting practice on track
7 p.m.--Track secure

Friday, Feb. 1
8 a.m.--Practice begins; LVMS gates, grandstands and pit road (via infield tunnel) open to the public
9 a.m.--Drafting practice on track
11 a.m.--Drafting practice on track
Noon--Track secure

*All times are Pacific Time.