BMW Team RLL – With little changed from last year to this year, and with four podium finishes in two years, including a 1-2 last year, it's hard to see Bobby Rahal's BMW squad as anything other than the class favorites. But Rahal is canny and smart enough to know half the reason for the success, besides the BMWs surviving on their own, was that their rivals incurred some self-inflicted wounds.

This is not to say that the BMWs won't be strong again in 2012, but the same level of pace shown a year ago might not be entirely matched. Case in point – the advances made by Corvette and Porsche, and by technical tire partner Michelin, should see those cars as a stronger package more similar to the characteristics shown by BMW and Dunlop on track last year.

Additionally, Sebring was one track where BMW lost out on a pole – AF Corse nabbed the top spot with its older Ferrari 430 a year ago. The driving lineup still includes defending class champions Joey Hand and Dirk Mueller, with Bill Auberlen and former Sebring overall winner Jorg Muller in the second car. Newcomers are a sports car veteran in Uwe Alzen and former Atlantics star Jonathan Summerton, keen to impress after two years on the sidelines. Summerton's role is third driver this race and Hand's replacement for conflicting rounds in the DTM. But overall, the gap among the top GT runners should be reduced at Sebring, leading into the rest of the year.

Extreme Speed Ferrari – ESM is into its third full season of ALMS and is probably due for its first class win at some point on the calendar. It wouldn't be a shock if it came at Sebring.

Risi's demise is ESM's benefit – technically, the Michelotto test mule Ferrari 458 that ran at February's winter test was listed under the ESM banner – and it was fast. The Patron-liveried 458s were too. The team now has a year of development under their belt with this car, including the full adjustment to paddle shifters, which premiered on this car last year.

With Risi's status uncertain for the remainder of the schedule, the potential exists ESM could adopt more Ferrari support, and that can only be a benefit. The team's No. 01 entry features a stronger lineup, with Guy Cosmo now joining Johannes van Overbeek and Scott Sharp, and the No. 02 completes the team's all-American lineup plan with Jeff Segal and Anthony Lazzaro late signings to partner Ed Brown. Either car could be in contention for a podium at the end of 12 hours.

Falken Porsche – Falken's in a tough spot for 2012, because now the team can't sneak up on anyone, as they did a year ago. It's Sebring, so rain is pretty much out of the question, much to the chagrin of the Falken engineers who put together 2011's most impressive rain tires. So where Falken is going to have to perform is in mastering the car setup on its new Porsche, not just gaining an advantage on its tires.

Falken does have its advantages, in team manager Derrick Walker and an all-pro driver lineup in Wolf Henzler, Bryan Sellers and Martin Ragginger. Henzler led the race in 2010, but that race for Falken was sabotaged, in part, by punctures. Falken might be a good pick for the rest of the season, but is more of a darkhorse at Sebring. Where they undoubtedly have upped their games this offseason is with one of the series' most active Twitter accounts.

Paul Miller Porsche – Paul Miller Racing is the third and least heralded Porsche squad, and while it's just sort of “there,” it's another squad that could be in line for a top-five if attrition takes its toll. The Miller squad's biggest change from 2011 to 2012 is a switch from Yokohama to Dunlop tires. Three of the four drivers that competed for the team in its Grand-Am spec Porsche at the Rolex 24, Bryce Miller, Sascha Maassen and Rob Bell, will run this car.

With tail-enders Jaguar, Panoz and Lamborghini not in this race as they were a year ago, the Miller Porsche faces an uphill battle to make it into the upper half of the class. That's not an indictment of the team, but rather an acknowledgement of the challenge they have chosen to undertake. A class podium, frankly, would surprise.

CHALLENGE CLASSES

PC – From top-to-bottom, the PC class and its participants really deserve a pat on the back for the amount of quality efforts put forth both for Sebring and the full schedule. This is going to be a fascinating subplot of the 12 hours, because there are a host of quality pro drivers split equally among the nine entries.

Also, the PC class drivers might have the most difficult job in the race. PC represents the “middle class” in-between the four prototype and four GT classes, and therefore, its drivers have to be able to run their own race, pass the GT cars without incident, and avoid being compromised when letting the leading P1 and P2 cars go through.

The pro drivers include Memo Gidley (No. 5 Muscle Milk), Kyle Marcelli (No. 8 Merchant Services), Bruno Junqueira (No. 9 RSR), Raphael Matos (No. 18 Performance Tech), Butch Leitzinger (No. 52 PR1), Colin Braun (No. 05 CORE), E.J. Viso (No. 06 CORE) and Dane Cameron (No. 025 Dempsey). Only Leitzinger, Marcelli and Cameron of that group have PC class race experience; Cameron is the defending class winner.

Where those cars will all rise or fall is in the hands of their co-drivers. The PC class regulations state that only one classified “platinum” or “gold” rated driver can run, alongside a combination of two “silver” or “bronze” ones. That means mostly semi-pro drivers to pure amateurs are mixed in, and how they handle the challenge presented by the class differences will determine how the class's race unfolds.

GTC – The nine GTC class entries have some quality teams and drivers, but will struggle to garner the proper recognition at the bottom of the race's nine-class structure.

There's a handful of genuine pro drivers thrown into these cars, with Michael Valiante, Sean Edwards, Nick Tandy, Damien Faulkner, Spencer Pumpelly, Leh Keen, Townsend Bell and Cort Wagner among them. Still, even their maximum efforts in the Porsche GT3 Cup cars won't see these cars doing anything except going slowest, likely some 20 seconds per lap off the overall leaders, at best. GTC has the same “pro-am-am” driver structure as does PC.

It's going to be difficult for anyone other than the class competitors to focus on GTC for its own race, as realistically, the GTC class's biggest challenge at Sebring is making sure its competitors stay out of the way of all the overtaking.