The 2008 world champion made his debut for Mercedes at the 2013 Formula 1 season opener earlier today.
The Briton told Sky Sports News: "I think it's great, I'm very happy, it's way better than we ever expected in the first race of the season. It's a great place to start.
"We're going to have to go back and take a look at why we were losing pace to other people, but I think the guys have done a great job to give us the pace we had. The car was feeling pretty good so I don't really understand why other people were pulling away.
"Malaysia is going to be tough but hopefully we can have a better result. It's going to be tough with the tyres but I had a longer stint than anyone else, but I just don't know where we lost ground."