The Formula One regulations underwent several changes prior to the 1995 season. The most significant change was to the engine capacity, which was reduced from 3.5 litres to 3.0 litres in order to reduce horsepower. Higher sidepods were required, together with raised cockpit side protection (above shoulder height; to be raised even more for ) and a larger cockpit opening than that of the 1994 cars. The front and rear wings were reduced in depth to lessen downforce, thereby reducing cornering speeds. To further reduce downforce, the flat-bottomed undertray which was made mandatory in was to now feature a large "stepped" section underneath each sidepod, raised about an inch higher and parallel to the wooden plank originally introduced in 1994. The overall height of the car was also lowered. Deformable structures, particularly the sidepods and nose section, were subject to more stringent crash testing. Many of these changes were in reaction to the deaths of Roland Ratzenberger and Ayrton Senna at the 1994 San Marino Grand Prix, who both died of head and neck injuries. Some of the circuits were also changed, with larger run-off areas featuring at tracks such as Monza and Imola.