The Monster Energy NASCAR Cup Series heads to Las Vegas Motor Speedway this weekend, with Sunday’s Pennzoil 400 presented by Jiffy Lube (3:30 p.m. ET, FOX, PRN, SiriusXM NASCAR Radio) serving as the capstone of a third consecutive triple-header weekend.
This is the first race of the season in which Monster Energy Series cars will use both tapered spacers, to reduce horsepower, and aero ducts to transfer air to the side of the car away from the front tires, which should foster tighter racing. That baseline rules package of tapered spacers and aero ducts will be in place on a majority of speedways measuring longer than 1 mile, but this is the first weekend of the season both are in use.
We explain that, plus much more, below to get you ready for Sin City.
RELATED: Full weekend schedule
Know the rules
NASCAR officials announced in October two baseline rules packages for the 2019 Monster Energy Series season, making a move to bolster competition with enhanced aerodynamic and engine configurations.
The different packages are tailored to the specific tracks on the Monster Energy Series circuit, with a combination of a smaller tapered spacer to reduce engine horsepower to a target goal of 550 (from 750) and aero ducts to foster tighter racing on a majority of speedways measuring longer than 1 mile.
Although both features — the tapered spacer and the aero ducts — will be in place for 17 of 36 races, five other races will have just the tapered spacer and not the aero ducts. Atlanta’s race last weekend, for example, did not utilize the aero ducts.
RECAP: Las Vegas testing
What about the rest?
The full-blown package that includes both tapered spacers and aero ducts debuts this weekend at Las Vegas Motor Speedway, where teams tested for two days in January. Similar tracks such as Kansas Speedway, Charlotte Motor Speedway and Kentucky Speedway will also utilize both — and so will 2-milers Auto Club and Michigan — but Sunday is the first race with the full package.
Other than Atlanta, Monster Energy Series races at Pocono (both of them), Darlington and the season-finale at Homestead-Miami Speedway will also deploy tapered spacers, but no aero ducts.
WATCH: Las Vegas drafting practice
All about that base-line
Beyond the tapered spacers and ducts, the baseline aero elements of the 2019 rules package are a taller 8-inch by 61-inch rear spoiler, a larger front splitter with a 2-inch overhang, and a wider radiator pan that measures 37 inches wide in the front tapering to 31 inches at the rear. Those base changes will be in place at every race next season with the intent of adding downforce to stabilize handling, a break from a trend of downforce reduction from 2015-18.
“For us, it’s really a focus on getting back to a true focus on the drivers and what NASCAR is all about — close side-by-side racing and trying to deliver more of that,” NASCAR Executive Vice President and Chief Racing Development Officer Steve O’Donnell said when the rules were announced last year.
NASCAR teams go from one mile-and-a-half track in Atlanta — OK, technically it’s 1.54 miles — to another in Las Vegas. Conditions will be vastly different, however. Atlanta’s old, weathered surface is notorious for chewing up tires. The surface at Las Vegas is smoother and doesn’t wear tires to the degree of Atlanta, which saw three seconds of drop-off time, per lap, over the course of a fuel run.
Goodyear officials are bringing a new tire setup for both Monster Energy Series teams and Xfinity Series teams this week. The left-side tire is brand new and hasn’t been raced on outside of testing at the track earlier this year — although Goodyear plans to use them at “many tracks” this season, according to a release. The right side tire was used last year at both Michigan and Texas, but not Las Vegas.
“Since the track surface at Las Vegas has proven over the years to be one that generates minimal tire wear, we have made a change to our tire recommendation for this weekend’s races,” said Greg Stucker, Goodyear’s director of racing. “Excessive heat is really the enemy of a race tire and tire performance. On surfaces that don’t naturally promote wear, it is important to design a tire that can handle and dissipate that heat, and this right-side utilizes a tread compound formulation which does that.”