Besides being the longtime chairman of Penske Corp., which he turned into a transportation empire, Roger Penske has formidable teams in NASCAR and in the IndyCar Series. He will have four cars competing in the Indianapolis 500 in May. He has put together a top-level sports car racing program. Oh, and he just celebrated his 81st birthday.

When will this guy ever slow down?

“My wife asks me that every weekend,” Penske said recently in an interview at the New York Stock Exchange.

Instead, he considers his racing enterprises “my fishing trip and golf game on the weekends.”

Then he laughed and added: “No, it’s a brand-building exercise. It’s an asset we have among our 56,000 people. We create winners. We have a positive impact on our customers and our brand. As long as I’m able, I want to be connected with motor sports because it’s something we know. We’re in the transportation business.”

And racing delivers an immediate bottom line.

“It’s like having your quarterly earnings every weekend,” Penske said. “When you have your quarterly earnings every weekend, you got to be on top of it.”

The 17-race Verizon IndyCar Series opens Sunday with a race on the streets of St. Petersburg, Florida. Team Penske has won three of the last four championships, with three different drivers: Will Power, Simon Pagenaud and Josef Newgarden. All three return to the team.

Helio Castroneves, the three-time Indy 500 winner, plans to return to Indianapolis this year to drive for Penske, but he is driving full time at Penske’s request in the SportsCar series.

In NASCAR’s top series, Penske added a third driver, Ryan Blaney, to join Brad Keselowski and Joey Logano. At the Daytona 500, his first race for Penske, Blaney led 118 of 200 laps and finished seventh. Logano and Blaney are the top two in the series standings through three races.

Penske, a native of Cleveland who was a champion sports car driver in the early 1960s, is best known in racing for winning a record 16 Indy 500s as an owner.

But Team Penske has won only one Indy 500 since 2009. That is a serious drought, so Penske will keep pushing because that is what he has always done. He likes racing because it is a good way to entertain customers, but he still badly wants to win.

“Roger Penske is the standard-bearer for IndyCar racing,” said Mark Miles, chief executive for Hulman & Co., which owns Indianapolis Motor Speedway and the IndyCar Series. “His contributions to the sport over the years have been incredible. He demands perfection. That approach to racing really lifts the bar. It’s a joy to see he’s not lifting off the throttle.”

Penske, in fact, likes to look down the road — and not just a couple of exits down the highway, either.

He was talking about ride-sharing businesses like Uber and Lyft when he suddenly said of his fleet of used cars: “Maybe in 2035, what we might do is have autonomous vehicles. After 9 o’clock at night, we can take a car to a central depot, clean it and fill it, and have it in your driveway ready for you in the morning.”

Penske, who is known as the Captain, would be 98 years old in 2035. But that seems to be just a minor detail.

“I hope I’m like him at his age,” said Pagenaud, who is 33. “I think he found a magic pill. When I ask him, ‘Are you going to take some rest?’ he says, ‘No. I’ve got to keep on going.’ I’m impressed with that mentality — think about keeping going so you don’t have to think about anything else. It’s a lesson of life — to be around him and see that. He’s a force of nature.”

The IndyCar Series faces a couple of challenges this season. The series is unveiling a redesigned car, which Penske, Miles and others believe will lead to safer but more entertaining racing at lower costs to team owners.

The series is also looking for a new title sponsor after Verizon announced in October that it would not renew its five-year contract that ends this year. The circuit’s TV deal with ABC and NBCSN expires at the end of the year too. Miles said he is optimistic that a media rights package could be assembled to increase exposure and entice a corporation to latch on as a new title sponsor.

Penske said: “We have to tie that together with social media. That’s where you’re going to get your eyeballs and your coverage from the standpoint of your fan base.”

During IndyCar races, he sits on the pit box of the Team Penske driver with the most longevity. That is now Power, 37, but Penske will be with Castroneves when he tries again to join A.J. Foyt, Al Unser Sr. and Rick Mears as the only four-time Indy 500 winners.

“He treats his business like he treats racing: It’s all in, 100 percent, never lift up,” Pagenaud said of Penske. “But having the chance to be around Roger, you have the chance to gravitate around different businesses, different industries, and you get to learn more about life. I feel enriched about the relationship.”

He added: “To be associated with Roger or Team Penske in general, it’s top-notch. If you want to be on the top level, you want to be with him.”