DOVER, Del. – Jimmie Johnson's NASCAR premier series career is a story of numbers.
Wins? He's at 74 and counting, eighth most in the series and second among active drivers.
Championships? Six, trailing only the seven won by NASCAR Hall of Fame members Richard Petty and Dale Earnhardt. Second-place finishes? He's got 46 of those, also second most among active participants.
The only item that Johnson can't put a number on involves retirement.
"No, I do not have a number and I have not picked a number," Johnson said Friday at Dover International Speedway, site of Sunday's AAA 400 NASCAR Sprint Cup Series race (2:30 p.m. ET, NBCSN, MRN, SiriusXM NASCAR).
"As a kid growing up racing and as I got in the sport, I didn't say 'when I get to this age, I'm going to step down.' I haven't had that conversation and have not picked a number with my wife and said, 'OK honey, this is the point that I am going to stop.' It's really based on feel, and I have Chani's support on that as well.
"When I feel like it's time, I am going to make that decision. Certainly (I) don't feel like it's time now."
That may be bad news for his fellow racers. Johnson is the only driver to qualify for the Chase for the NASCAR Sprint Cup every year; he's won multiple races every year since his first full season in 2002 and he has finished outside the top five in points only twice during his 14-year career.
In a sport that changes constantly, Johnson and success have been linked since Day 1.
"I remember watching Rusty (Wallace) pick a number and then remember talking to (him) in years following that and I still think he's mad he stopped," Johnson said. "I think he feels like he could be out here racing with us and winning races.
"So conversations with him, with Dale Jarrett, with other guys ... I have always been curious. Why, when, what tells you to stop? Mark (Martin) tried a half dozen times to retire and couldn't walk away.
"So I want to make sure I do it once and not keep coming back."
What he's looking for, he said, is "the moment."
"That moment that you say, ‘Alright, it's time.' When that shows up, then I will step down."
The final race in this year's Challenger Round is set for Sunday. It will be Johnson's 500th career start, and his fifth-place points position makes him a shoo-in to be one of the 12 drivers who advance into the Contender Round.
Becoming a member of Hendrick Motorsports, paired with sponsor Lowe's and crew chief Chad Knaus, the success that followed has "been a life-changing experience," Johnson said, "something I dreamed of.
"But I still couldn't have dreamed this big and have this much take place for us."