Sebastian Vettel has conceded that he performed below his best during the 2018 Formula 1 season.

The Ferrari driver threw down a serious challenge to eventual champion Lewis Hamilton during the first half of the campaign but won only one race of nine after the summer break.

Hamilton wrapped up the title with two rounds to spare, and ended up finishing 88 points clear of Vettel in the standings.

Vettel slipped off the road and found the wall while on for a win in his home grand prix at Hockenheim, and was also set back by spins in Italy, Japan, and the United States.

“Looking back, I haven’t been at the top of my game,” said the German.

“I can be better than I was at times this year. I think I need some time for myself. It has been a quite difficult and exhausting year for me.

“I don’t think I ever had any problems raising my hand if I made a mistake. I don’t think I need to change things upside down but certainly I can adjust and get stronger.

“Having said that though, I think we also had a lot of races where we got everything out of the car and the package and I felt that I did everything I could. I was happy with that.

“For now I need a bit of time just to shut things down. We have a little bit of time to digest and analyse.”

Vettel’s slump was in part also attributable to a drop in pace from Ferrari in general, which erred on its development path in the back half of the season.

“We did a step back towards the end of the year which enabled us to be more competitive again, but I think we’ve understood what went wrong,” he explained.

“I think we had a lot of lessons, it was a tough year in general. I think the team is strong and the team has potential but surely it was a lot of things that happened inside the team.

“The passing of our chairman, Mr (Sergio) Marchionne obviously had an impact and was tough.

“It’s up to us to look into every single detail and make sure we come out as a stronger group.”