 In late 1993, Senna had already signed for Williams for the 1994 season, 20 years later, Dennis revealed that Senna would have remained with McLaren had McLaren signed Peugeot earlier (as he believed a 'works' partnership to be essential to success in F1), but felt obligated to stay with Williams.At the time, it was speculated that Senna believed that despite Peugeot's recent success with its 3.5 litre V10 in endurance sports car racing, having won Le Mans in 1992 and 1993 as well as the 1992 World Sportscar Championship, the engine would not stand up to the rigors of Formula One where the engines were under high strain and were constantly being pushed to their limits, nor did he believe that the Peugeot engine had enough power to challenge the Renault V10; both beliefs were proven correct over the course of the 1994 season.The McLaren MP4/9 Peugeot which followed was closely based on its predecessor, but was not as successful as the engines proved woefully unreliable (eventually becoming infamous for failing spectacularly) and promised development from Peugeot never eventuated.