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Nico Rosberg said an incorrect setting meant he did not get the Energy Recovery System (ERS) boost he was expecting while fighting Lewis Hamilton for the lead at the US Grand Prix.

Rosberg led for the first 23 laps of the race but was passed on lap 24 at Turn 12 as Hamilton lunged up the inside and made the move stick. Hamilton went on to take the victory, meaning Rosberg is now 24 points down in the championship with 75 points still up for grabs.

Although Rosberg did not realise it at the time, he had set his ERS boost for a delayed response rather than an instant boost as Hamilton came past.

"When I saw him coming I decided to go for extra boost, but I never got it," Rosberg said. "I just found a new thing that I made a mistake because I used the wrong thing to get me more ERS. I thought I was using the right thing but there was a delay in that one. If I did it with a button it would be immediate, but with a switch there is a delay, so I never got the extra ERS. So I had a big derate, which is why in the last metres he got a good jump on me. So, that was a mistake that I didn't know about.

"I went for extra boost but the way I did it, it only comes on with a delay so I didn't get extra boost at that particular moment."

Rosberg admitted he could have done a better job defending the corner too.

"I am sure I could have done better, but it is a judgement thing. If I defend a lot he will brake late on the outside and get me on the next one, so I thought indicating I am closing the door would have been enough to stop him from trying, but it wasn't. Because I was part way over already and I thought that was enough for him to think he should not try, but it wasn't."

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