Lewis Hamilton admits he is mystified by his struggle to race competitively with his Mercedes car.
Hamilton slipped back to finish seventh in the Abu Dhabi Grand Prix after being fourth on the grid, and contending for pole position in qualifying.
He said: "It's very confusing. I was half a second up on my [qualifying] lap, 100% if I hadn't have made a mistake I'd have been on the front row.
"But when I get to the race I don't know what happens. I really struggle."
Hamilton was on target to potentially match or beat Red Bull's Mark Webber in qualifying when he ran wide over a kerb and broke his rear suspension.
He had been confident of contending for at least a podium position, but went backwards in the race, in which his fastest lap was a second slower than team-mate Nico Rosberg, who finished third.
"It was like I had another 50kg in the car," he said. "I was just too slow. Just no pace."
Hamilton's race was hampered by being caught in traffic after his first pit stop, but he said that would have made no difference.
"Even if I wasn't in traffic I wasn't fast enough," he said. "Even if I was ahead I would have been overtaken, I just wasn't good overall."
Hamilton has been struggling to have confidence in the car's braking performance this year and he said he was hoping the Mercedes team would find solutions for next season.
"I'm just hoping, with the tyres and the car, we can do some work over the winter and make the car work for me a bit better," he said.