One of the main changes was the change of the engine and gearboxes, as Simtek were given the old Benetton gearbox alongside the Ford-Cosworth EDB engine, which replaced the Ford-Cosworth HB engines. The Benetton gearboxes were used as part of the team's deal to employ Verstappen, who was loaned from his position as Benetton's test driver. The S951s were the last cars to be completed of all the 1995 F1 teams' chassis, arriving at the first round of the championship in Brazil with minimal testing.