Ferrari's Fernando Alonso ended the final day of Formula One's first pre-season test at Jerez on Friday with a flourish despite lingering concern about the performance of his new car.

Spain's double world champion set the fastest lap of the day at the southern Spanish track, a result that pleased local supporters even if times mean very little at this stage of development.

He was unable to do much in the afternoon due to a hydraulics problem.

“There is a long way to go until (the first race of the season) in Australia in terms of how many days and how many tests we can do,” said Alonso whose car has been dubbed the ugliest Ferrari in years.

“The progress in these four days has been quite big for us. Maybe not in performance or times or whatever ... but definitely all the tests we did and all the understanding of the car has been positive for us,” he told reporters after doing a mere 39 laps and a best time of one minute 18.877 seconds.

“We will arrive in Barcelona much more prepared than how we arrived in Jerez,” added Alonso.

The next test is at the Circuit de Catalunya from Feb 21-24, with the season starting in Melbourne on March 18.

Alonso's team-mate Felipe Massa said on Wednesday that Ferrari had a lot of work to do while technical director Pat Fry made clear he was far from happy.