The new 2019 competition package introduced this week for the Monster Energy NASCAR Cup Series features considerably more downforce than the current configuration, thanks to a taller spoiler and a wider splitter.
To Kyle Larson, who ran a Chevrolet set up with the new rules package during a Goodyear tire test at Phoenix on Wednesday, the difference was obvious.
“We did about half the day or a little bit more in 2019 aero package,” Larson said on Friday at Dover International Speedway. “It just has way more grip. We ran through some different tire compounds and stuff to get an idea. All of them had a lot of grip, so you could carry a ton of throttle. The acceleration obviously wasn’t the same as the ’18 package, just because you have the bigger blade and stuff on the back. A lot more drag.
“So acceleration wasn’t quite as much. It was pretty crazy how far you could run in the corner and then also how quick you could pick the gas up.”
The 2019 rules feature a 1.17-inch tapered spacer—the same as the 2018 configuration, with engines capable of generating 750 horsepower—for tracks shorter than 1.33 miles. For tracks 1.33 miles and longer, the 2019 rules include a .922-inch spacer at approximately 550 horsepower—a 37.5-percent increase over the package run at the widely acclaimed Monster Energy All-Star Race in May.