Honda and Formula One champions Renault are in confident mood after wrapping up their final tests before this week's season opener in Bahrain.
Honda's British test driver Anthony Davidson set an unofficial lap record at the Valencia circuit in eastern Spain on Thursday and said the car felt good.
"It has been generally fast and well balanced all week," said Davidson, who supports compatriot Jenson Button and Brazilian Rubens Barrichello as Honda's third driver in Friday practise at grand prix weekends.
"We're all looking forward to Bahrain now, I think we'll be strong there."
Honda have completed 27,000 kilometres of testing since the end of November, with 14,700km in 18 days of running since the new RA106 car made its debut on January 25.
Throughout February, each of the team's two cars lapped well in excess of a race distance on each day of testing, with Davidson alone doing 412 laps of the Valencia circuit in three days last week.
Renault, winners of both titles last season with Fernando Alonso becoming the youngest champion at the age of 24, have also been pounding the Spanish test tracks.
"Our strong performance in winter testing has given everybody a genuine boost in motivation," said technical director Bob Bell.
"It has been an intensive winter of preparation and we sincerely believe we have a strong chance of successfully defending our championships."
The new R26 has done nearly 14,000km of testing, an increase of 73 per cent compared to the same time last year, according to the team. The cars are also running an average of 12 per cent further every day compared to 2005.
Finnish test driver Heikki Kovalainen said they could feel very satisfied.
"Our engine is reliable and Michelin tyres performed well this winter so I think we have a real chance for the first race," he told the Renault F1 Web site.
"We all will be very disappointed if we are not fighting for the win in Bahrain."
Ferrari's Michael Schumacher, the seven-times world champion, is also confident his team have turned the corner after a dismal 2005 and would be contenders at Sakhir today week.
"We were happy with the car's speed before, and now we can be satisfied with the reliability as well," he told his Web site after testing at a cold and wet Mugello circuit in Italy.
"We should be well prepared for the start of the season and we should be one of the leading four teams," added the German.
"Renault is still making the best impression so far, followed by Honda, Mercedes (McLaren) and ourselves.
"But we'll have to wait until the season gets underway to find out if that's true."