Jenson Button says he initially underestimated how tough the competition would be in his first full year of sports car racing.

The 2009 Formula 1 world champion teamed with Naoki Yamamoto to claim the Super GT title, with the Team Kunimitsu Honda duo edging out defending champions Nick Cassidy and Ryo Hirakawa by three points.

Button told Sportscar365 that it took a while to get acquainted with the GT 500-spec Honda NSX-GT package at first before getting up to speed and mounting a successful title bid.

“Before I did Super GT the aim was always to win the championship,” said Button.

“But I didn’t realize how tough the competition was until I started testing. I was like, ‘Oh, wow, I’m a second off the pace’, so it was a long way to go before I could find the key to finding the pace.

“It’s so different to drive, and how to get the tires to work and finding a setup that works for you. It’s been a tough year and an exciting year, and I’m so happy to have clinched the title.”

Button said he “learned so much” about race craft during his first full year in sports car racing.

He entered 2018 with next-to-zero experience in closed-wheel racing beyond guesting in the 1999 Spa 24 Hours, but quickly found his feet doubling up in Super GT and the FIA World Endurance Championship with SMP Racing.

Button’s first Super GT win came at Sugo in September, while he scored his first LMP1 podium in the most recent WEC round at Shanghai with Vitaly Petrov and Mikhail Aleshin.

He explained that of the two series, overtaking in the WEC was “so much easier” to get used to because of the smaller performance gaps in Super GT.

“There are 15 GT500 cars and then the GT300 class where there’s 20-odd cars, so there was always a fight,” said Button.

“You’re always fighting past the backmarkers and it’s always really hard to hold someone off in traffic as well.

“I’ve learned so much about overtaking and positioning the car so people can’t get past. There’s so much going on, it’s very different to what I’m used to.”

Button has heaped praise on his co-driver Yamamoto, who became the first driver in 14 years to win both the Super GT and Japanese Super Formula titles in the same season.

“My teammate was awesome and he really helped me through a lot of it,” he said.

“His speed first of all, and the guy works very hard on improving the car. A lot of our debriefs are in Japanese and I just sit there, but afterwards, we talk.

“He’s done a lot of work this year, so I’m very grateful to him.”

Title Defense a Priority for 2019

Button is expected to defend his Super GT title next year, although Honda has yet to make an official announcement on its 2019 program.

However, SMP Racing recently confirmed that the 38-year-old Englishman would be absent from its LMP1 driver lineup at both the Sebring and Spa WEC rounds, because of clashing commitments in Japan.

Button described Super GT as like “proper club racing” because of its down-to-earth setup, but with the heavy manufacturer presences of Honda, Lexus and Nissan whose presidents often come to watch the racing.

“I’m loving Super GT so whether we won the championship or not I still would have wanted to continue next year,” he said.

“It’s such good racing, a lot of very talented drivers and three manufacturers. It’s awesome and I’d definitely be up for next year.

“I’m an ambassador for Honda, so wherever Honda is, is an opportunity.”