Vettel completed 102 laps on his first day in the Red Bull RB9.
"So far, I think we can be pretty happy," he said. "Mark [Webber] had a good couple of days to start with and I took over today. It was great to get back in the car, to get rid of the rust and to get back in the groove again."
"The first feeling is good and the car is working well. It’s difficult to judge the speed, but in terms of reliability it looks pretty good. For today we accomplished what we set out to achieve – which was to put a lot of laps on the car."
Vettel added a note of caution to his optimism, insisting that the first test is difficult to judge.
"At this stage it’s very difficult to judge anything else," he added. "It could be that there is a favourite after these three tests, but it could turn out to be completely different in Australia because it’s a different track with different characteristics. I expect the Championship to be at least as tight as last year, as the regulations haven’t changed so much."
While the 25 year old likes to be near the front, he realises the times matter little at this stage of the season.
"In terms of the times, it’s always nice to be on top, but if there’s one phase of the year where it matters least, it’s here. Now is the time to do our homework. It’s good for us to do a lot of laps, to see that the car is working well and we’ll go from there."