Sebastian Vettel says he feels the 2010 F1 season will be a close run affair after taking part in his first test of the year at Jerez.

Having missed the opening test in Valencia, Red Bull Racing joined its rivals in Spain last week to turn the first laps with the new RB6, which was also launched at the second pre-season test of the campaign.

Despite mixed weather conditions and a technical issue on the final day, Vettel declared himself happy with the opening test of the year and said he was glad to have got some of the early teething troubles with the new machine out of the way.

"The car felt alright immediately, even though the weather was far from ideal for testing a new car," he told F1.com. "But we all know that such conditions can occur over a race weekend, so it's always good to have data to hark back to.

"Overall I would say that we can be very satisfied about how things developed. We were able to put in quite a lot of mileage, even if we had a problem on day four, which kept me in the pits for quite a while just when it started to get dry. But I would say it's better to face problems at test session than at races."

When quizzed on any surprises he had seen during the test, Vettel replied that the new regulations had led to surprises throughout the field ahead of a season he believes will be a close run affair.

"There is not just one surprise; I think the biggest surprise is when you look at everyone. If you look at the cars they are not just different colours but also different shapes, with a different philosophy behind their design," he said. "They are all more or less close together, within a couple of tenths, so ourselves, Ferrari, McLaren and Mercedes I think are pretty close. But the Toro Rosso looks quite strong as well. If you read into the lap times a bit, it is fairly close.

"There are a lot of things still to happen before Bahrain, and a lot of new parts coming for us, and of course for the other teams as well. But so far it looks very close."