Formula One: Vettel feels good vibrations in new surroundings

The four-time world champion has been fastest on both the opening days in southern Spain and will hand over the reins to teammate Kimi Raikkonen for the rest of the test.

Vettel's start to the new campaign is in stark contrast to his disastrous first test ahead of a troubled final season with Red Bull last year.

The 27-year-old spent almost the entirety of his time in Jerez in the garage as he completed just 11 laps over two days in a sign of what was to come as he sank from world champion to fifth in the driver's standings.

"It could be worse, especially compared to last year at this stage," said Vettel after completing 88 laps despite a rain interrupted afternoon on Monday.

"We did a lot of laps, especially today. I think it is normal in winter testing if you see anything running a bit odd to take the time to stop and have a look which unfortunately takes time, but the new engines seem to work well even in these conditions.

"I'm happy, especially at the end with the wet running that I kept the car on the track. We already have a long night ahead, I didn't want to make it any longer for the guys in the garage.

"I hope that tomorrow and the day after that Kimi finds at least the same if not better reliability."

Vettel's times have put reigning double world constructors champions Mercedes in the shade despite Lewis Hamilton and Nico Rosberg racking up over 200 laps in their first days in the new W06 car.

However, Vettel insisted there is still a long way to go if Ferrari, who finished nearly 500 points adrift of the German giants in fourth place in the constructors' champions last season, are to challenge this campaign.

"I think we have to remember where we're coming from, there is a lot of change," added Vettel.

"There are a lot of new things. There is a lot of stuff that we have learned and from that point of view the most important thing is to keep running, to learn about the car, the numbers and make sure we are ready for the next test.

"Mercedes are running a slightly different approach. They have done some very long runs, so in thar regard it is difficult to judge.