|Focus points Straight-line speed. The cars are flat-out for large sections of the lap (22s in Sector One and 19s in Sector Three), so the main focus for the engineers revolves around how much downforce to strip off the car while continuing to give the drivers a compliant machine through the high-speed twists of Sector Two.
Unique difficulty No other corner in F1 resembles the legendary left-right-left flick at Eau Rouge. It’s been eased over the years, making it slightly less of a challenge, but the g-forces and the incline remain unique. The drivers approach the corner at 310km/h (190mph) and they experience a 2g compression at the bottom of the hill, before being subjected to 4.6g lateral through the right-hander, while climbing 190 feet towards the exit at Raidillon.
Biggest challenge The weather. The track is located in the Ardennes, a mountainous region of Belgium that’s infamous for its unpredictable micro-climate. Rain has become a regular feature of the race and it was at Spa-Francorchamps in 1997 that the first-ever Safety Car start took place on a water-logged track. Complicating matters further, the track is often dry in one section and wet in another, forcing the drivers and engineers to think on their feet.