Sebastian Vettel says he'll walk away from Formula 1 when he is either too slow, or not passionate enough about the sport.
This weekend's Bahrain Grand Prix marks the German's 200th grand prix start, putting him in an elite club.
However, unlike the last driver who reached 200 – Nico Rosberg – Vettel, 30, has no plans to quit F1 any time soon.
"No, you just give up when you're too slow," he told Corriere Della Serra when asked if there was a right age to stop racing.
"Or when you lose the passion, if you no longer feel the excitement and nervousness before the race start.
"If it happened to me, I would change job, leaving space for young people."
Pressed on Rosberg, who walked away after winning the 2016 World title, Vettel added: "He has his reasons for leaving, and they’re only in his head.
"It can be discussed, but to make such a decision you need balls."