F1 is not the only major racing series to kick off this weekend. The combined fields of the brand new FIA World Endurance Championship (the first global endurance title for 20 years) and the IMSA American Le Mans Series meet to provide an enormous 64-car grid for the 60th Anniversary 12 Hours of Sebring, the oldest endurance race in North America. A field so big that part-time entries were turned away.The battle at the absolute sharp-end may be a little flat, the withdrawal of Peugeot leaving Audi uncontested on sheer pace, but a very strong field of closely-matched petrol-engined contenders (including David Brabham, Karun Chandhok, Nick Heidfeld and more) are expected to provide a fantastic race - and of course Audi still has to complete the distance to win it, no guaranteed feat at this track with this many cars.The LMP2 class is the best it has been in years and for once is very much worth watching, whilst GT will surely be its usual fraught battle between Ferrari, BMW, Corvette and Porsche.