After much speculation about what teams would make the entry list for this year's Petit Le Mans, 58 cars have been accepted for entry into the sports car race held next week at Road Atlanta.

This year's Petit, as in 2010, serves as a joint round of the American Le Mans Series and Intercontinental Le Mans Cup and, as such, features a bumper crop of additional entries not otherwise seen on U.S. soil. Of the 13 LMP1 entrants, nine are ILMC-entered; those include the outright favorites in the Audi and Peugeot diesels. Audi's new R18 TDI coupe makes its first race appearance on U.S. soil after running an updated R15++ model of its 2010 24 Hours of Le Mans-winning, open-top prototype at the 12 Hours of Sebring.

Peugeot splits into the two factory 908s – the No. 7 featuring French aces and part-time IndyCar pilots Sebastien Bourdais and Simon Pagenaud sharing with Anthony Davidson, provided the Englishman is good to recover from injuries sustained in a biking accident – and Team ORECA Matmut's grandfathered 908 HDi FAP which won overall at Sebring and features Nicolas Minassian and Marc Gene joining Nicolas Lapierre.

United Autosports' ALMS debut comes as the highlight in the five-car LMP2 class with an Oak Pescarolo Judd on Dunlop tires.

The GT field is 19 cars strong with six additional GTE Am entrants also guaranteed a start in the 53-car race field. Five European entrants join the usual 13 in ALMS's GT ranks, and Robertson Racing also has one of its two Doran Ford GT-Rs entered. The one AM car of particular note is AF Corse's Ferrari F430, to be driven by Michael Waltrip Racing partner Rob Kauffman with Rui Aguas and Justin Bell.

The Challenge classes are where things get a little interesting with regard to who starts. Provisionally, full-season entrants in LMPC and GTC who have started every ALMS race will be “locked in,” provided they meet minimum qualifying requirements. There are five each that, on paper, meet that distinction.

All cars that do not make the 53-car field will be considered alternates, and IMSA chief operating officer Scot Elkins clarified that all cars on the entry list are full-season entrants, even if they have not actually started all events.

“These cars are all on the entry list, but that doesn't mean they will all start,” Elkins said.

If cars were to drop out prior to the race, Challenge cars would get the benefit of moving into the field. Additionally, Elkins clarified the number change system for conflicts between full-season ALMS and ILMC cars, which then changed on Thursday.

“We looked through the entry list, and found only three conflicts,” he said. “So rather than add a ‘0' in front of all ALMS cars (as was done in Sebring), we added a ‘9' in front of the ones that it hits. This will be much easier for the corner workers, who said it was hard to call ‘0' whatever car it was.”

That was to alleviate the situation of Sebring where there was a No. 1, a No. 01, and a No. 001 (Audi, Highcroft HPD and Extreme Speed Ferrari, respectively). Those ILMC full-season entrants gained number priority, as Rebellion Racing's No. 12 and two GTE Am cars (No. 62 and 63) will wear their usual numbers.

While the number switch had to feature a '9', due to some concerns over branding identity, IMSA has now switched back to '0' in front for conflicting numbers. It means Risi Competizione's Ferrari will wear No. 062 at Petit Le Mans as they did at Sebring, rather than what would have been No. 962 under the original number switch. Genoa's No. 063 and Autocon's No. 012 are the only other conflicting numbers.