Racing in Cup full time for a few more years was just something that I couldn't commit to. His resume features 18 Cup Series victories throughout his 15-year career.
The 43-year-old Sadler made the announcement Wednesday on Twitter.
Next on the schedule is Saturday's race at Bristol Motor Speedway.
A 15-year premier series veteran, Kahne now drives the No. 95 Chevrolet for Leavine Family Racing.
I've thought about this decision for many months, if not longer.
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The couple had previously experienced financial difficulty, but didn't show any signs of current financial stress on social media. Prosecutors said that Christopher Watts is being held in protective custody because of the publicity surrounding the case.
Citing the toll the "grueling schedule" has taken, Kahne said he plans to spend more time with his son, Tanner, and with his sprint vehicle teams. "I need to spend time doing the things I enjoy and love".
Sadler made his Xfinity Series debut in 1995.
He has 748 total starts across NASCAR's three national series, including 527 in the Cup Series. Sadler earned two more wins at Texas and Auto Club Speedway in 2004 while driving for the now defunct Robert Yates Racing.
That was the only time he finished in the top 10 in the Cup points. "The Sadler name has become synonymous with motorsports in Virginia". Kelley Earnhardt Miller told Sadler that even though his primary sponsor was leaving at the end of the season, she believed they could still provide him with a full-time ride in 2019. "I felt terrible this year missing my kids' All-Star games".
"It's time for me, as a Dad, to help my kids pursue their dreams", Sadler wrote on his various social media channels.
"I've had a great career in racing and met so many awesome people and fans along the way, some that I'll remain in touch with for life. Hopefully, that's how they'll remember me; a fan himself, who just happened to be on the other side of the fence".