Lewis Hamilton said his new Mercedes chassis had transformed his competitiveness in Sunday's United States Grand Prix, enabling him to finish fourth.
"The car was night and day different compared to where it was in Abu Dhabi, so I'm sure the new tub helped," he said.
"I'm really just so happy that I could contribute and get some points for the guys. They've been working so hard all year and they've had so many difficult races in this half of the season.
"To finally have a half decent qualifying, move forward, utilise the tyres and have life left in them, makes me really, really happy."
Hamilton had struggled to match the performance of his Mercedes team-mate Nico Rosberg in the recent Indian and Abu Dhabi Grand Prix.
The team then found a crack in the chassis of the car he used in Abu Dhabi and replaced it with a new one for Sunday's race at the Circuit of the Americas.
He resisted late pressure from Ferrari's Fernando Alonso to retain his position.
"I could see Fernando was catching, so I was just looking after the tyres and waiting until he started to push," he said.
"He started to push, so I reacted a little bit. When he was going to bring out a tenth, I was going to bring two tenths.
"When he was going to bring three, I was going to bring four. I'm really, really happy I could do that today."
The result meant Hamilton climbed to third above absent Kimi Raikkonen in the drivers' championship. The Lotus driver was absent as he underwent sugergy on his back.
"That doesn't mean anything to me," said Hamilton. "Plus the guy that was in third wasn't even racing."
Source: AFP
