Johnson expects to be stronger in '07

The Hendrick Motorsports driver is aiming to be the first man since Jeff Gordon in 1998 to secure back-to-back titles, and he is optimistic for his title defence.

"If you look in the history books you will see that there aren't a lot of back-to-back champions in our sport," said Johnson, who has never finished outside the top five in the Nextel Cup standings.

"But this team has overcome a lot of hurdles in the last few years and this will be just another challenge for us.

"We seem to get stronger every year and I expect to see that continue this season. We are very optimistic."

Johnson also believes that Sunday's qualifying session is very important, even if it only decides who will start on the front row for the Daytona 500.

The rest of the grid is decided by the results of the Twin 150 races which will take place just a few days before the season-opener.

"Qualifying is important for us because is decides where we will start in the Twin 150s, and you want to ahead of any trouble that might develop," he said.

"The driver doesn't play a great role in single lap qualifying (at Daytona), it's more about the hard work our race team puts into the restrictor plate programme."