Portimao, Portugal - Testing on the Portuguese Algarve draws to a close Thursday for five Formula teams with Renault's Nelson Piquet Jr saying the top teams are beatable this season and Toyota's Timo Glock believing he can be one of the top five drivers in 2009.

"It's going to be a very interesting season. There have been countless changes such as new wheels, new aerodynamics and the KERS system," Piquet Jr said.

"Whichever team works hard and gets used to the new rules faster will definitely have an advantage."

Renault are testing in Portimao alongside the McLaren-Mercedes team of Lewis Hamilton, Williams, Toro Rosso and Glock's Toyota.

Piquet Jr's teammate Fernando Alonso also feels "anything is possible" this season but the two-time world champion finished last on his first day of testing Wednesday.

Glock's testing was even more eventful with the engine of his TF109 briefly catching fire, leading to a break of several hours.

Despite the initial setback, Glock, who finished 10th in the drivers' standings last season, believes he can do much better this year and that the smaller teams will have a greater chance of finishing races ahead of McLaren-Mercedes, Ferrari and BMW-Sauber.

"My first impression of my car is very good. I'm happy with it," the 26-year-old told Deutsche Presse-Agentur dpa.

"Everyone is pretty much starting all over again because there have been so many rule changes and while, in principle, the top teams like McLaren, Ferrari and BMW should look good this year all the other teams have been given the chance to get closer or even to pass them out and so maybe finish ahead of the top teams. Of course we will have to wait and see what happens in the first race."

The 2009 F1 season begins with the Australian Grand Prix on March 29 in Melbourne. (dpa)