Button confident of Honda progress

"We've been putting in a lot of hours to make sure the car is reliable and running smoothly," he told a Tokyo news conference.

"I must say I'm happy with the way things are going. We're making improvements at every test in many, many areas. And for me, I'm happy also because the car is very drivable. It's a car we can really build on."

Honda had a dismal 2007 season with a poorly-handling car that made life difficult for Button and Brazilian teammate Rubens Barrichello.

The team finished eighth overall with just six points, all scored by Button, and have since recruited former Ferrari technical director Ross Brawn as principal.

Button was more than three seconds off the pace set by McLaren's Heikki Kovalainen, and Honda were the slowest of the manufacturer teams, on the final day of a test at Jerez in southern Spain last Thursday.

Button, however, is confident the team will make significant progress before the start of the season and also throughout the year.

"I'm optimistic that throughout the season we will improve a lot," he said. "I'm also optimistic that even with our first step, which will be for Melbourne, aerodynamically we are going to make a good step forward.

"The difference with this car compared to last year's car is this car is a driveable car. It's a car that you... you understand the car, so you can work with the car so you can improve the car. While last year we just didn't understand the car, the way the car was working for the first part of the season.

"And to make changes was very difficult, because it was very inconsistent. So this year I'm very happy to drive this car even though we are still lacking in speed, the driveability is much better.

"You can feel the car a lot more, which is very important to progress with the car and improve the car."