Only a couple of years ago, it looked like the top tier of prototype endurance racing was in trouble. Peugeot shut down its program, leaving the LMP1 category all to Audi to dominate. Only six cars entered the Petit Le Mans in 2012, and the season was cut short. But the top class in the FIA World Endurance Championship has since blossomed. And it only looks poised to grow further. Audi and Toyota will each be back on the grid this season, joined by Porsche . But the latest news has Lotus stepping up to the big leagues also. (Well, sorta: the German-run squad uses the Lotus name and colors, but has no more to do with the automaker than the Formula One team of the same name.)The Lotus LMP1 will be based on the same Lola-based T129 chassis used until now in the LMP2 class, with former F1 driver Christijan Albers leading the driver lineup. In addition to Audi, Toyota and Porsche , the solitary Lotus entry will also compete against privateer Rebellion Racing in a nine-car LMP1 grid throughout the season.