One question has persisted for stock-car racing prospects for decades: What’s the best path to success as a NASCAR Cup Series driver?

Some start their journeys in go-karts. Some grow up in Legends cars and stay on pavement through late models. Others hone their craft on dirt, then transition into the NASCAR Regional world.

But eventually, when an aspiring racer breaks into NASCAR’s three national touring series, they will first land in either the NASCAR Craftsman Truck Series or the NASCAR O’Reilly Auto Parts Series. There, those drivers hope to learn valuable lessons and traits that will carry over to Sundays as Cup Series stars.

MORE: Cup Series standings

All three series’ vehicles — from Cup to O’Reilly to Truck — have vastly different characteristics from each other. To some extent, that has impacted how Cup teams of today evaluate the talent developing in NASCAR’s lower-tier national series as they determine who has what it takes to shine on Sunday.

Denny Hamlin and Brad Keselowski both climbed through NASCAR’s ladder system in the 2000s. Long before either co-owned a NASCAR Cup Series team, each had to impress prospective car owners through the O’Reilly Auto Parts Series and Truck Series. One benefit at that time was a similar DNA between the O’Reilly car and the Cup car used on Sundays. Saturday’s racers often used Cup-built chassis with similar motors, building habits, skills and techniques that often translated to Sunday success.

But now each series has evolved, highlighted by a radically new Cup platform introduced in 2022 through the Next Gen car. The Next Gen vehicle features departures from previous stock-car designs, such as independent rear suspension, a flat carbon underbody and a sequential five-speed transaxle in place of a four-speed H-pattern transmission.

Much of the known calculus of driving a Cup car changed in a hurry. Four years later, we’ve seen a handful of drivers jump from the Truck Series directly to Cup, notably Carson Hocevar, Todd Gilliland and Zane Smith.

So how do the trucks and O’Reilly cars of today compare to the Next Gen car?

“It’s hard. It’s really, really hard,” said Hamlin, driver of the No. 11 Joe Gibbs Racing Toyota and co-owner of 23XI Racing. “The trucks probably drive more similarly to the Next Gen car, but it’s really hard to evaluate one over the other.”

Austin Cindric, the fifth-year driver of the No. 2 Ford for Team Penske, spent the majority of his time developing his skills in the NASCAR O’Reilly Auto Parts Series, racing four full seasons on the tour and collecting the 2020 championship before graduating to Cup full time in 2022 — the inaugural year of the Next Gen car.

“I think the narrative during my rookie year was it was a great year to be a rookie, just because there’s a lot of newness and no one’s learned the car yet,” Cindric, who won the Daytona 500 to kick off that rookie campaign, told NASCAR.com. “I feel like it’s kind of a double-edged sword because I think now, if you’re a rookie moving into the series, it’s much more of a known quantity. And at the end of the day, it comes down to the people that are around you, the people that can support you, understanding and gaining that knowledge of those cars and what that transition looks like from just driving and how to extract the lap time out of the car.”

Before heading to the O’Reilly Auto Parts Series, Cindric spent one full season in the Craftsman Truck Series, racing for Keselowski’s former race team Brad Keselowski Racing, an outfit that fielded efforts for some of today’s best Cup Series drivers. In addition to Cindric, 2023 Cup champion Ryan Blaney and 2026 Daytona 500 winner Tyler Reddick drove for Keselowski.

Now 27 years old with nearly five full seasons of Cup racing and three Cup Series wins, Cindric sees value in both series’ paths. The aerodynamics and drag all transfer from the Truck Series to Cup, he noted. The O’Reilly Auto Parts Series offers longer races more comparable to the Cup Series, allowing Saturday racers to experience how a track evolves over the course of a 300-mile contest and the increased tire degradation that comes with it.

“I think there’s a lot of great lessons that I’ve taken from both,” Cindric said. “Obviously, I spent four years in the O’Reilly Auto Parts Series, so that was huge. I learned how to be a NASCAR driver in that series in those cars and learned a ton. So I don’t think there’s a right or wrong way of how to do it. It’s more about what you extract and what you’re able to apply.”

One benefit to Cindric’s racing upbringing was a diverse path that pushed him through sports cars and V8 Supercars, manifesting a unique skill set on road courses before adapting to NASCAR’s ovals. In his opinion, the broader a driver’s resume, the less concern there should be about creating bad habits in the Truck or O’Reilly Auto Parts Series that would inhibit a Cup driver’s performance — simply because they should be able to adapt what each respective vehicle requires.

“I felt like I was definitely the exception when I was coming up through the ranks as far as how many different types of cars I’ve driven and different experiences I’ve had,” he said. “And not that I’m saying that I was a trailblazer for that, but (I’m) certainly seeing that that’s becoming much more of the norm, where drivers are getting in road-course cars or going and racing on dirt and doing all these experiences while they’re still young. And I think that really helps for drivers to be open-minded and easily adaptable. So avoiding creating habits, I think, is kind of somewhat eliminated in the sense that I feel like a lot of the drivers coming in now are much more of that flexible mindset.”

That adaptability, in large part, is what Hamlin looks for from the ownership seat as he evaluates talent to elevate to the NASCAR Cup Series for 23XI Racing.

“I just really look at race craft,” Hamlin said. “Can someone make a move and put their car in a position that I know is a very difficult position, and they come out of it ahead? It really doesn’t matter to me what vehicle that that person that I’m eyeballing is in. It makes no difference because I believe the great drivers can adapt to whatever car that they’re in. I think that it just doesn’t matter. You learn race craft and then you just adapt your style to get the speed out of the vehicle and the machine that you’re in.”

Corey Heim may be the best modern example. Heim, the 2025 Craftsman Truck Series champion who dominated the series in 2024 and 2025, already is a two-time winner in the NASCAR Cup Series. He was victorious in the summer’s biggest races at Naval Base Coronado and the Brickyard 400 at Indianapolis Motor Speedway.

Heim has limited experience in the O’Reilly Auto Parts Series but an extensive and extraordinary successful Truck résumé.

“The trucks are definitely more similar than the O’Reilly cars, but they’re all just totally different honestly,” Heim said on Dirty Mo Media’s “Door Bumper Clear.” “The main difference from the truck to the Cup car, getting technical, is you cannot yaw the Cup car out. I mean you’re driving it like as straight as possible. You can’t really counter-steer and yaw the Cup car out. The truck, I feel like I always just drove it off the right rear, just slung it into the corner, did everything I could to feel all of the sideforce and all that nature.

“But the Cup car, it’s like you’re just driving it on a railroad track. And if you break off that railroad track, then you’re in trouble. The feel of the tire’s a lot different. Of course, you’re going from an H-pattern to a sequential shifter. There are a lot of differences, but if I were to develop in anything, I think a truck might be a better avenue right now. But it’s apples to oranges.”

For Keselowski, there is so much difference between today’s Cup car and the other series’ vehicles that few of the specifics translate on a one-to-one basis. But those who are scouting prospective talent can still observe key decision-making capabilities that can indicate a driver’s ceiling.

“I think oftentimes, what makes somebody a great Saturday driver that can maybe transcend into being a great Sunday driver is greater than just their talents,” said Keselowski, co-owner of RFK Racing and driver of the No. 6 Ford. “It’s their ability to really understand second- and third-order decision making, which is the concept of since the races are so long, you can’t make a move and just think about the immediate success of it. You can’t use your strategy and just think about the immediate success of it. You have to be able to think of it over the terms of not just a 500-lap or 500-mile race, but oftentimes over a 30-some week season.”

Those decisive moments could shape not only a race but a future or career. On Fridays and Saturdays, those decisions are made against competition that is still learning the ropes. 

On Sundays, those moves are being made against 35 of the top stock-car drivers in the world.

“It’s gotten to the point now where if you look back 30, 40 years ago, you would say that you could have talent and great work ethic, and that would get you to Cup,” Keselowski said. “And that’s not enough now. The competition’s too good. Everybody’s got talent. Everybody’s got work ethic. You have to be a great decision-maker over the course of a really long race.”