For the first time, at least in recent years, Sebring will see three different prototype classes thanks to the addition of the new Challenge class. Here, we take a look at what cars will be racing this weekend, who will be in them, and what their chances are.

No.007Aston Martin Racing (Lola-Aston Martin) Harold Primat/Adrian Fernandez\Stefan Mucke
No.07 Team Peugeot Total (Peugeot 908 HDi FAP) Alex Wurz/Marc Gene/Anthony Davidson
No.08Team Peugeot Total (Peugeot 908 HDi FAP) Sebastien Bourdais/Pedro Lamy/Nicolas Minassian
Drayson Racing (Lola B09/60-Judd) Paul Drayson/Jonny Cocker/Emanuele Pirro
No.12Autocon Motorsports (Lola B06/10-AER) Bryan Wilman/Tony Burgess/Pierre Ehret

With the Sebring entry list devoid of Audi for the first time since 1999 on paper you would expect Peugeot to walk it, taking the class win and the overall win. Since their appearance in endurance racing diesel cars have swept all before him, and the line-up for the two 908's are typically star-studded, especially the no.08 car, which sees possibly the strongest line-up in a single 908.

However, to paraphrase a cliche from another sport, races are not won on paper, especially endurance races. The two Peugeot's topped the week's first two timed sessions, the first by nearly three seconds over the next P1 car, but there is so much more to Sebring than speed. That said a car does not win Le Mans by being desperately unreliable. However, there are many unknowns in 12 hours of racing, not least the cars they still have to beat to P1 and overall honours.

Once more the series' various sanctioning bodies and organisers have tweaked the rules to bring the petrol cars closer to the diesel drinking counterparts, Drayson Racing believe they have 50 extra horsepower compared to last year, handed to them through winter development and changes in regulation.

However, similar changes in recent years have seen little impact on the track, so, especially with the first tests now completed it is difficult to be anything but pessimistic.

But, Sebring (perhaps for the first time since the arrival of the diesels) will give us a genuine comparison of diesel to petrol cars, thanks to the other team that have crossed the Atlantic to Sebring – Aston Martin.

Aston Martin were the best petrol powered car at Le Mans last year, and though their driving trio is maybe not the strongest Aston could have mustered for the race they should present us with a more accurate comparison compared to running against smaller teams, such as Autocon or Intersport.

No.1Patron Highcroft Racing (HPD ARX-01c) David Brabham/Simon Pagenaud/Marino Franchitti
No.6 Team Cytosport (Porsche RS Spyder) Greg Pickett/Klaus Graf/Sascha Maassen
No.16Dyson Racing (Lola B09/86-Mazda) Chris Dyson/Guy Smith/Andy Meyrick

Sebring sees the ALMS run to full ACO regulations, with separate P1 and P2 classes, through the bulk of the season with see the two combined into a single Prototype class. However, the meagre three cars entered for the class still sets alarm bells ringing a little.

But, what a three cars! Three established ALMS teams and cars and what could be one of the battles of the race.

The class sees reigning P1 champions Highcroft drop back to P2, remaining with Acura, running a ARX-01c chassis – which, though badged HPD is a developed version of the car Acura entered the series with in 2007 and that dominated the class with Lowe's Fernandez Racing last year. The car, and team, have the ability to be dominant, and have to be the favourites for class honours, and could even be one of the first teams ready to take advantage of Peugeot slip up at the front of the field.

However, the other teams also have the ability to race the P1 cars before they are blended into a single entity. The Porsche Spyder is one of the great cars of the ALMS after Penske Racing's cross-class battle with Audi, and Pickett's CytoSport squad have shown themselves capable of similar feats, most recently and memorably at Petit Le Mans when Klaus Graf ran from the back to the field to catch the Peugeots at a wet Road Atlanta.

The final entry in the class also sees a great ALMS name – Dyson Racing. Rob Dyson's squad have cut their team in half over the winter with only one Lola-Mazda due at Sebring. The team struggled early last season with the new car, but showed definite signs of improvement later in the year. 2010 sees the team able to use the Isobutanol fuel developed by BP. Though they will be saddled with 30kg of ballast, the fuel could make an impact, with headline statistics stating a 25% better fuel economy, on the series, and on the automobile industry as a whole.

No.11Primetime Race Group – Joel Feinburg/Kyle Marcelli
No.36Genoa Racing – Andy Wallace/JR Hildebrand/Tom Sutherland
<strongNo.55 – Level 5 Motorsports – Scott Tucker/Christophe Bouchut/Mark Wilkins
No.89Intersport Racing – Mitch Pagerey/Brian Wong/David Ducote
No.95Level 5 Motorsports – Scott Tucker/Ryan Hunter-Reay/James Gue
No.99Green Earth Team Gunnar – Gunnar Jeannette/Christian Zugel/Elton Julian
All cars ORECA FLM09-Chevrolet

The debut of the Le Mans Prototype Challenge class could be a barnstormer is testing performances are anything to go by.

Times thoughout the winter test saw the teams very closely matched, a trend that was taken to whole new levels in Wednesday's first sessions when five cars were covered by little more than half a second – only the Intersport entry was outside the bracket.

Despite the class being a new addition to American racing the entry list contains several respected, and familiar names, both in terms of teams and drivers. Not least Intersport, for whom their LMPC tilt is now the main priority after Jon Field's massive accident on Monday. The class is also the new home for Primetime Race Group who will be familiar to ALMS fans after running a GT2 Dodge Viper in recent years.

Though class rules prevent teams from running more than one driver deemed 'professional' the field also sees several visiting drivers from elsewhere in the motorsports galaxy. Andy Wallace, part of the Genoa Racing team, along with Indy Lights champion JR Hildebrand, that topped that Wednesday session has two overall wins at Sebring amongst a glittering CV.

The main question is the ability of the cars to last 12 hours. The cars, as Formula Le Mans competed in hour long races. ORECA who build the cars are very capable of making cars that can last 12 hours and beyond, but Sebring is a very tough place for a chassis to have its longest race to date.

Photo credit: James Boone