Denny Hamlin and Kyle Larson have had polar opposite starts to the Chase. While the Joe Gibbs Racing veteran has just found his first top-five finish in the first four Chase races, the two-time Cup winner has had a worst finish of 5th, with two victories and a second-place finish. And while it seems like Chevrolet has wiped out Toyota’s early-season dominance, the question arises: what exactly happened to Toyota’s performance?

Several analysts have tried to answer that question. Dale Earnhardt Jr. pointed to the splitter change enforced by NASCAR at North Wilkesboro as the starting point of what he described, not necessarily as Toyota’s downfall, but rather Chevrolet and Ford’s gains. Dale Jr. broke it all down on his Dale Jr. Download podcast with stats since the change at North Wilkesboro in July. 

“They won 60% of the races before the change, and now they’re at 33%,” Dale Jr. said. “So, they are still good. They are still top 10, and you can see it by looking at the running order or watching the race on Sunday, but they’re not at the front of the field, dominating Ford and Chevrolet, at least since this has been taken into account.”

It wasn’t just the win percentage Dale Jr. outlined; he also touched on other stats showing that Toyota’s dominance seems to have evaporated since North Wilkesboro. According to the stats presented by Dale Jr., Toyota led 47.9 percent of laps before North Wilkesboro, and that percentage has since fallen to 34 percent. Toyota had 38.5 percent top ten finishes before the change and 35 percent after. 50 percent was Toyota’s top five finish rate, which has dropped to 42 percent after the splitter change. 

Dale Jr. didn’t only present the stats that show Toyota is experiencing a drop-off; he also explained the changes teams had to make to their splitters since the North Wilkesboro race. 

“Teams added new struts to the front of the splitter. And what the teams want to do with this car is make the underneath kind of like a banana,” said Dale Jr. “They want to arc the bottom of the car. They want the nose to drop down. So you’ll see the cars, if you walk through the garage, they have all the cars sitting up on jack stands, and then they’ll have jacks underneath the front splitter. That’s holding that front splitter in place so that the car can go through the tech shed and pass all of the tolerances.”

“But out on the racetrack, they kind of want all that front stuff to kind of sag down as much as possible,” he added. “And some teams had this really going well, and it creates kind of a banana effect underneath the car, which is better aerodynamically.”

The front splitter is basically a horizontal plate attached at the bottom of the bumper which divides the airflow to increase downforce and stabilise the cars at high speeds. Essentially, the change made is to reduce the downforce because NASCAR felt that there was already too much of it. 

But that reduced downforce has allowed both Chevrolet and Ford to come into the championship picture. Several times this season, it felt like Toyota would have a runaway winner. First, it was when Tyler Reddick won five in the first nine races this season. The 23XI driver still has the most wins this season. Next was when Hamlin passed Reddick for the championship lead and held it right until Bristol. 

However, Toyota hasn’t really shown a falloff in pace or performance; the stats may indicate that, but studied carefully, they say more about the improvements that Chevrolet and Ford have made. 

Before North Wilkesboro, Joey Logano was hovering around 20th place on the leaderboard, and then he got his first win of the season for Team Penske before grabbing another at Richmond. Logano’s resurgence began at North Wilkesboro, and after entering the Chase in 9th, Logano’s Bristol victory shot him into touching distance of Larson and Hamlin. 

Larson didn’t win a single race until the Chase began. He was running well all season long, picking up handy points, and his 13 top-five finishes prove that. Five of those came since North Wilkesboro. And his two Chase wins are just further proof of how hard the Chevrolet has come back into the championship fold. 

While Logano and Larson have five wins collectively since North Wilkesboro, Hamlin has none. In fact, he has five top-five finishes since North Wilkesboro, same as Larson, but he doesn’t have any wins and hasn’t even finished 2nd apart from the race at North Wilkesboro itself. 

In Kansas, Denny Hamlin and Toyota were predicted as early favourites, as is the case with the upcoming races at Vegas and Charlotte, all intermediate tracks. Toyota were supposed to be far ahead of the Ford and Chevrolet at these tracks specifically. But Hamlin finished third in Kansas, behind even Austin Cindric, who ended up with his season’s best finish in the No. 2 Penske Ford. 

The component change in the splitter hasn’t necessarily held up Toyota’s dominance. But it has allowed the Chevy and the Fords to get in contention, which was expected from powerhouses like HMS and Penske. The race in Vegas is going to be a big test for JGR Toyotas, and perhaps even decide their fate in this championship battle.