Fernando Alonso is convinced he will be able to fight for this year's Formula One world title from day one.

After opting to skip the first test in Jerez a fortnight ago to focus on his fitness, Alonso returned to the cockpit of his Ferrari for the first time yesterday for the start of the second test in Barcelona.

The 31-year-old Spaniard completed a day-high 110 laps in the F138, posting the third quickest time at the Circuit de Catalunya behind Mercedes' Nico Rosberg and Kimi Raikkonen in the Lotus.

Like team-mate Felipe Massa before him after his first day in the car at Jerez, Alonso declared it to be "on another planet" compared to a year ago.

In testing last season, and over the first few races, Ferrari found themselves hopelessly off the pace.

Despite a fortuitous win in Malaysia from Alonso due to the rain-hit conditions, it was not until an in-season test in early May the team finally resolved their issues, allowing him to mount a title charge, only to fall three points short in his battle with Sebastian Vettel.

A year on, and Alonso feels much more content behind the wheel of this season's car ahead of the season-opening event in Australia now less than four weeks away.

"We will be strong in Australia, and that is where we need to be," said Alonso.

"We need to improve on what we did last year because obviously it was not enough. We finished second and we want to finish first.

"To improve on the first part of the year is not going to be too difficult, so we are relatively confident.

"I fought for the championship last year with a car that was two seconds off the pace in the winter.

"So we need to be positive and think that we will fight for the championship again this year if we improve the car a little."