SEBRING, Fla.—Cars are on track and at speed preparing for the 2017 IMSA WeatherTech Mobil 1 Twelve Hours of Sebring.
There have been practice sessions for support classes running since Wednesday, March 15, but the big cars—the WeatherTech cars—started on Thursday morning, with three sessions including night practice.
The race starts at 10:40 a.m. Saturday, March 18, and runs for—you guessed it—twelve hours, until 10:40 at night.
The track will be busy all day Thursday until 9 p.m. and from 8 a.m. to 6 p.m. Friday, . with Friday featuring practice and qualifying for WeatherTech and ending with the Continental Tire Challenge Sebring 120 which starts at 3:40 p.m.

There is always one in the crowd who has to color outside the lines. Despite this off-track excursion, Porsche T Team driver Frederic Makowiecki turned the fastest GT Le Mans lap, 1:57.109 at 114.9 mph. Chris Jasurek/Epoch Times