McLaren's Formula One driver Lewis Hamilton of Britain and Ferrari's Felipe Massa (background L) of Brazil wave to the crowd before the Brazilian F1 Grand Prix in Sao Paulo November 2.- Xinhua/Reuters

Lewis Hamilton believes cost-cutting changes will make it "very tough" for him to repeat as Formula One champion next year.

Governing body FIA and the F1 teams agreed to a series of measures for 2009 last Friday, which include longer-lasting engines, limits on expensive testing and cheaper, off-the-shelf engines for smaller teams.

"I don't think it will make it easier," Hamilton said on Tuesday. "With the new regulations it's going to make it very tough to win the championship again."

The sweeping changes come as automakers reel from the global financial crisis. Honda pulled out of F1 this month after Super Aguri quit in April. FIA said the first batch of changes for 2009 will help larger teams cut costs by about one-third over 2008.

"We have less testing obviously but I think we as a team are in a position to pull together and make a difference in some other way," Hamilton said. "But everyone's in the same boat."

Changes to be introduced after next season will be even more radical with races maybe shortened to save money and refueling banned, which could dramatically alter the spectacle for fans.

Hamilton's McLaren team boss Ron Dennis called it a "challenging period."

"It's amazing how many different things happen in a year but all we're thinking about is how we can continue in the sport and continue to put on a good show," Hamilton said.

Hamilton missed out on becoming the first rookie champion by one point last year, but rebounded to become the youngest F1 champion at 23 in November - by a single point.

Hamilton overtook Toyota's Timo Glock on the final bend at the season-ending Brazilian Grand Prix to finish fifth and secure the title after Ferrari's Felipe Massa had won his home race as he needed to.

Hamilton expects more of the same close racing next season despite the dramatic changes. "We don't know who's going to be quick, surely we're going to be at the front, with Ferrari maybe, BMW, but you never know. Maybe there's going to be a fourth team up there with us."

Hamilton added that becoming F1's first black champion "was hard" because of having "to break down the barrier and it was not easy but we got there, and I have been accepted very well."