Jenson Button defended Honda's 2008 Formula One car on Thursday and said the team were making good progress despite looking well off the pace in testing.

"We've been putting in a lot of hours to make sure the car is reliable and running smoothly," The Brit 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 team mate 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.

"Our pace is definitely not going to be enough to get us near the front, but there's a lot more to come before the first race," Button told Autosport after that test.

"We're continually improving and that's the most encouraging aspect.

"Throughout last season, we didn't really see much progress so now we're seeing reasonably big gains and that's a huge positive."