IndyCar and Formula 1 often find themselves competing, but when it comes to which is bigger, there's only one winner.
Many former F1 drivers find themselves jetting to America to take part in IndyCar, with Indy500 winner Marcus Ericsson, Romain Grosjean, Alexander Rossi and Takuma Sato all fitting within that category.
Additionally, some drivers who made their name in IndyCar have been linked with F1 seats in recent years, particularly Colton Herta and Pato O'Ward.
IndyCar has often been seen as the alternative to it's more popular big brother, but a growing popularity, specifically in the US, has seen it become more and more of a competitor.
Scott Dixon, a six-time IndyCar champion, drove a Formula 1 car back in 2004 for one-day testing with the Williams team, and the 41-year-old has remained a fan of the sport ever since.
But with more and more F1 drivers coming to the series in recent years, Dixon explained that IndyCar is certainly now an attractive option for drivers around the world.
"I've always really appreciated what IndyCar is, from driving the car that it is and how raw it is and the competition is a big one," said Dixon.
"And I think it's been a big draw for most of the Europeans that come in this direction, knowing that if they get into a small team, which, really, the small teams are gone these days. The budgets are fairly sizable for everybody to achieve and run competitively.
"So I think that's been the draw that they can come over and race fairly with the whole field. And we've seen how successful that's been, for many of them that come over."
However, when it comes to finances, sponsorships, broadcasting rights and sheer popularity, IndyCar still trails F1 quite considerably.
"You know, F1 is still the pinnacle man," Dixon added.
"You look at the sheer size of it, the sheer revenue, the TV numbers, you know, it's the prize.
"As far as a purist and loving IndyCar for what it is and how competitive is and how fun the cars are and the cool tracks we get to go to, I personally prefer IndyCar.
"But then you look at just the sheer size and popularity and some of the cool machinery that Formula 1 has, you know that's a different topic.
"I was lucky enough to drive one of them in the early 2000s. But, yeah, it's kind of a hard question to answer, I think yes and no, I don't know. That's a tough one."
Now competing in his 22nd year of IndyCar series, the 42-year-old may have seen his opportunity to drive in Formula 1 pass by, but Dixon did admit he'd "have a crack at it" should an opportunity arise.
"I don't know who would be crazier, the F1 team or myself. That's a pretty big hypothetical. What it comes down to for me is just my pure love for racing.
"So if there was an opportunity that was hard to turn down, you know, of course, I would have a crack at it. But I love what I'm doing."