Jerez, Spain - Kimi Raikkonen rolled back the years with the fastest lap for Lotus on the first day of 2012 Formula 1 testing.The 2007 champion, making his comeback after two years in the World Rally championship, looked at home right from the start of a chilly morning in southern Spain and completed 73 laps.His best time of 1min19.670 was quicker than any lap in testing at the track in 2011.That could be explained by a number of technical factors and any early excitement had to be tempered with the knowledge that the fastest driver in last year's Jerez test was Rubens Barrichello, who went on to score only four points for Williams all season's end.'POSITIVE DAY'Raikkonen said: "It was a positive day. The lap times don't matter today. I'm happy with the balance of the car, which feels good, and the fact that we didn't have any major issues."Also, I did more than a race distance today and had no physical problems, which is good," he said.Raikkonen was his familiar self afterwards, facing a media scrum outside the former Renault team's motorhome with deadpan replies and barely a flicker of emotion beneath his oversize cap, Finnish reporters were thrilled. As one explained, a happy 'Iceman' walked with a spring in his step whereas when things were going less well Raikkonen showed all the verve of a snowman. Paul di Resta was second-fastest for Force India ahead of Nico Rosberg in his 2011 Mercedes and Mark Webber in a new Red Bull.The session was twice red-flagged, first when Daniel Ricciardo stopped his Toro Rosso on the track with an oil-pressure problem and again when Sauber's Kamui Kobayashi ran out of fuel.Webber had to wait to get out on the track with the title-winning team's plans hampered by a plane carrying the RB8's rear wing assembly being diverted from Jerez to Seville due to early-morning fog."Sometimes we can't control Mother Nature so we risked it a bit tight on the schedule and we paid a bit of a price, which can happen sometimes," said Webber, winner of the final 2011 race in Brazil."There are obviously lots of changes. Aerodynamically, the concept is a bit different because of the regulations, but we are satisfied," he added.NEW CARSWith an array of new cars on a track for the first time, the McLaren stood out as the only car other than the Mercedes and ageing HRT not to have the new stepped nose that all have adopted to satisfy the revised aerodynamic and safety rules.Jenson Button, 2009 champion, appeared happy enough with his day a marked change from 2011 when McLaren started testing with a car soon shown to be hard to handle and way off the pace.Button said: "There are no niggly areas with the car, which is nice. Quite different to last year. I'm happy. The front wheels are on the front, the rear wheels are at the back, it feels like it's going in the right direction, and when you turn right, it goes right. Sometimes that hasn't been the case."He gave Raikkonen a reminder of what he can expect for 2012, when there will be six champions on the grid, by overtaking him near the end of the session."He's obviously in a very competitive car, he said of the former McLaren driver, and whatever they did today - low fuel or whatever - it was still quick. So, fair play, they've had a good day."