Four-time IndyCar champion Scott Dixon says current teammate Tony Kanaan and former teammate Dario Franchitti are among those whose form have convinced him he can race well into his 40s.
The Chip Ganassi Racing driver, who is 36, told New Zealand Stuff: "There are a few key guys in the championship, in TK [Kanaan], Helio Castroneves and Juan [Montoya] – they all turned 42 this year. And Dario [Franchitti] was 40 or 41 when he retired. They've helped the longevity.
"I think I've got a good four, five or six years to play with but in motor racing that can change next year. My focus is on what is at hand and the and the IndyCar Series is the most competitive series in world right now, I enjoy that competitive side."
Dixon, who finished third in this year's 24 Hours of Le Mans also hinted that sportscar racing may feature more prominently after his open-wheel career ends.
He said: "Motor racing could quite easily fill next 10 years of my life, beyond that I don't know. It depends what direction a lot of things take, with myself and my family. I'm not even sure where I'll be living at that point.
"Right now I'm focusing purely on what's in front of me."
Frustrated by the 2016 season
Dixon added two more wins to his tally in 2016, bringing his total to 40, which places him fourth in the all-time Indy car victory list. However, he admitted that as defending champion to finish only sixth in this year’s title race had been painful.
"We definitely let a few get away," Dixon said. "Those are the ones that hurt and you focus on more than anything.
"If you generally look at the performance of the #9 car throughout season, it was very strong. We just had three or four races where we had mechanicals or strategy pitfalls that took us out of it and would have transformed our championship position.
"It was definitely a frustrating one, with not so many highs and a lot of lows. For myself to finish out of the top three for the first time in 12 years was not good."