IndyCar’s teams recently completed four days of testing at Sebring in preparation for the season opener the weekend after next in the streets of St. Petersburg, Florida.

After six increasingly monotonous years with the same Dallara-Honda spec car, IndyCar is trying to rebuild itself this year with the new Dallara DW12 chassis and competing 2.2-litre turbo V6s from Chevrolet/Ilmor, Honda and Lotus/Judd.

Other changes for the new season include the arrival of Beaux Barfield as race director in place of Brian Barnhart who remains IndyCar’s director of operations. Barfield is a former F2000 racer who worked as chief steward of the American F2000 and Atlantic series before joining IndyCar. Two-time Indy 500 winner Arie Luyendyk joins Barfield in race control this year as Barfield’s driving expert.

The Sebring tests showed that new formula or not the formbook looks much the same as in recent years with the Ganassi and Penske teams on top, and almost everyone else looking about where you might expect them to be. Here’s my assessment of the 26 drivers and 16 teams competing in IndyCar this year.

Dario Franchitti and Scott Dixon will be hard to beat in Chip Ganassi’s lead pair of Honda-powered cars. Dario and Scott have combined to win the last four IndyCar championships for Ganassi and both drivers and team are sure to make sense of the DW12 Dallara more quickly than most others. This will be Franchitti’s 16th year racing Indy-type cars and Dixon’s 12th while Ganassi’s team is as experienced and solid as their drivers.

Penske’s trio of Chevrolet-powered DW12s driven by Will Power, Helio Castroneves and Ryan Briscoe look likely to once again feature as Ganassi’s biggest challengers. Power is at the height of his career and ready to win a championship. Castroneves and Briscoe should provide ideal team support and it will be interesting to see if the new Ilmor/Chevy engine can produce any advantage for Roger and his team under IndyCar’s restrictive rules.

Andretti Autosports will continue to be a thorn in the side of Ganassi and Penske. Ryan Hunter-Reay is going into his 10th year in Indy-type cars and should be able to win some races while James Hinchcliffe is also sure to run near the front in his second year. And Marco Andretti will have no excuses.

Rubens Barrichello (above) ran quickly at Sebring and will bring new life to KV Racing. It will be interesting to see how he fares in the rough and tumble of IndyCar street racing, let alone the ovals. Old friend and team-mate Tony Kanaan (below) hopes Barrichello’s presence will help make for more consistent performances at the front of the field. EJ Viso has shown he’s quick but needs to produce some results.

Bobby Rahal’s Rahal Letterman Lanigan team returns full-time to IndyCar this year with Takuma Sato leading the Honda-powered team. Sato is quick and with Rahal’s team he has the chance to mature into an IndyCar contender. Promising GP2 graduate Luca Filippi will join Sato (below) in a second RLL car starting at Indianapolis in May.

Bobby’s son Graham goes into his fifth season in Indy-type cars and second with Ganassi’s ‘junior’ team. Graham is a very good, race-winning driver who needs to break through to the top level. He must do it in the next year or two. Team-mate Charlie Kimball is a solid journeyman and steady racer.

Justin Wilson tackles his eighth season in Indy-type cars and has rejoined Dale Coyne’s team with whom he won at Watkins Glen in 2008. Coyne is running Honda engines and Wilson will be quick in some races. His team-mate is Brit James Jakes who ran his rookie IndyCar season last year.

JR Hildebrand continues for his second IndyCar season with Panther Racing and Chevrolet engines. Last year Hildebrand’s biggest day came at Indianapolis where he got closer to winning without doing so than any man in the grand old race’s 100 years. JR hopes for better things this year.

Talented but taciturn Brit Mike Conway has joined AJ Foyt’s Honda-powered team this year and may feature from time to time. Simon Pagenaud is another talented, but largely unheralded driver, who will run his first full IndyCar season this year with Sam Schmidt’s team and Honda engines.

Sebastien Bourdais will race full-time in IndyCar this year for Jay Penske’s Dragon team with Lotus/Judd engines. It will be interesting to see if the talented Bourdais – a four-time Champ Car champion remember with Newman/Haas – can make the team competitive. After racing DTM cars for a few years Katherine Legge returns to America as Bourdais’ team-mate.

Oriol Servia did a superb job with Newman/Haas last year in the team’s final season finishing fourth in IndyCar points. This year Servia drives for Dreyer & Reinbold Racing with Lotus/Judd engines. Another talented driver with Lotus/Judd engines is Alex Tagliani who drives this year for Brian Herta’s team, winner of last year’s Indy 500 with Dan Wheldon.

Last year’s promising Indy Lights champion Josef Newgarden will run his rookie IndyCar season with Sarah Fisher’s little Honda-powered team. Ed Carpenter, winner at Kentucky last year, has formed his own team with Chevrolet engines while Simona de Silvestro will run her third IndyCar season with Keith Wiggins’ HVM team and Lotus/Judd engines.

As always with a new formula there are many unknowns, but the stars of the show are likely to remain the Ganassi and Penske teams and drivers.