Felipe Massa targets 'triple improvement' for Williams F1 team

The Grove-based outfit sealed third place in the constructors' standings for the second successive year in the Brazilian Grand Prix earlier this month.

But despite scoring four podiums, Williams has failed to win a race in 2015 and is currently 407 points adrift of champion Mercedes in the constructors' with one race to go.

"To have a car to fight for the championship, you need to do a triple improvement because Mercedes is far away in front of everybody," Massa, who was in London last weekend to contest the Race of Champions at the Olympic Stadium, told Autosport.

"To beat them, you need to do better work from now till the first race.

"We're working to be better next season. This season was a good season but we're never 100 per cent happy.

"We need to concentrate and improve things which didn't work so well this year and not repeat them next year and be stronger.

"From now till March, we need to prepare a good car. That's what will count.

"If you speak to the team, everyone is happy, everyone is motivated.

"We just need to work and see where we are next year."

Massa said he was "not surprised" Williams managed to carry its 2014 form into this season, even if the ultimate pace had not been what he had hoped for.

"I think we believed we could finish the season with the second quickest car but it was a very good championship anyway," he said.

"Red Bull had their problems, with the engines and everything, but we didn't.

"I think that it has been a very positive season."