The 32-year-old Finn was testing in Valencia on Monday ahead of his return to Formula 1 this year after two years in rallying.

Trackside operations director Alan Permane said: "From the first run he was pretty much there."

Raikkonen said: "It was nice to get back into the car. It's quite a few years since I last drove."

Raikkonen was driving a two-year-old Renault R30 at Valencia's Ricardo Tormo circuit in Spain, and will continue into a second day on Tuesday.

He will drive the team's 2012 car for the first time at Jerez in next month's first pre-season test.

Permane added that it was impossible to say whether Raikkonen was fully up to speed as there was no benchmark for the car on that track and on the tyres Raikkonen was using.

It was in a more updated specification than the car that ran at Valencia in pre-season testing in 2010 and the tyres were demo rubber provided by F1's new supplier Pirelli, as opposed to the Bridgestones on which it ran two years ago.

Pemane said: "It's very difficult to know where he should be but he was pretty much on the pace on the first run. He didn't find a whole lot of pace during the day.

"I don't see any reason why he won't be on the pace - you can tell he's a very, very experienced driver.

"It was very clear we were working with a former world champion. It was a good day."

Permane emphasised that the test was purely aimed at getting Raikkonen used to the speed and performance of an F1 car after so long out of the cockpit.

"There's not a lot we can learn [technically]," he said. "It's far more to get him used to the car and comfortable with the team. It's a head start before we get to Jerez."

Raikkonen has a reputation for being taciturn in public, but Lotus did not find him that way at the test.

"He must have two faces - one for [the media]," Permane said. "He's perfectly normal.

"He was very happy to sit and talk about the car for as long as it takes. He's very open."

Raikkonen told Sky Sports News: "Of course it takes a little while to get used to it, but the main driving, turning, braking doesn't take many laps. But learning about the team, the tyres, the car will take some time."

The 2010 car, with which the team's former driver Robert Kubica impressed greatly that season, has been repainted in the black and gold colours adopted by the team since they rebranded themselves from Renault to Lotus last year.

Raikkonen is not allowed to drive a 2011 car because F1's testing restrictions forbid it, but teams are allowed to run outside these rules - which strictly limit testing - as long as the car used is at least two years old.

Raikkonen, who won the world title with Ferrari in 2007, last raced in F1 in 2009. He was dropped by the Italian team at the end of that season in favour of Fernando Alonso and switched to rallying, where he competed without success.

Lotus signed Raikkonen after it became clear that Kubica, who is recovering from serious injuries sustained in a rally crash in early 2011 and then in an accident at home this month, would not be fit to race at the start of this season.

BBC.CO.UK