Patrick confirmed on her Facebook page that she would not be returning for the NASCAR organisation she has been part of since 2013.
Although she has not scored a race win, Patrick has sat on pole for the Daytona 500 and scored seven top-10 finishes. After coming into stock car racing with massive support from go.daddy.com, the ending of that sponsorship prior to the 2016 season saw her car backed by a range of different companies.
The 35-year-old started this year with Nature's Bakery as the primary sponsor, but the company pulled out before the season began. After a court battle that ended in a settlement, the company sponsored four more races this season but only one with Patrick. It sponsored three races with SHR teammate Clint Bowyer.
Patrick pointed to sponsorship as a key reason behind the 2018 decision.
“It has been my honour to drive for Tony Stewart, Gene Haas and everyone at Stewart-Haas Racing for the past six seasons,” said Patrick via Facebook.
“Together we earned a Daytona 500 pole, seven top-10 finishes and we also had some exciting racing along the way.
“My time driving for them, however, has come to an end due to a new sponsorship arrangement in 2018. Sponsorship plays a vital role in our sport, and I have been very fortunate over the course of my career, but this year threw us for a curve. Our amazing partners, such as Aspen Dental and Code 3, stepped up in a big way on short notice this year and I am incredibly grateful.
“I wish SHR the best of luck with their new sponsorship and driver. Thanks for the memories. Right now, my focus is on the remainder of the 2017 season and finishing the year strong. I have the utmost faith in myself and those around me, and feel confident about my future.”
Patrick's profile was built in the Indycar Series where she took a race win in 2008 at the Twin-Ring Motegi in Japan.
Her jump to NASCAR was facilitated by go.daddy.com which had backed her in Indycar.
Patrick's best points finish in NASCAR points has been 24th, which she accomplished in 2015 and '16. She is currently 28th in points with 10 races remaining.