The first public appearance of the BT50 was at the 1981 British Grand Prix, where the team's lead driver, Nelson Piquet, used it in practice. He set a practice time 0.7 seconds slower than his qualifying effort in the Cosworth DFV-powered BT49. The BT50 handled poorly but still recorded through the speed trap, some faster than the BT49. Piquet, a firm advocate for the BMW engine and believing, like Ecclestone, that the road to success in the near future was with a turbocharged engine, tested the BT50 throughout 1981. Testing was plagued with unreliability; in one testing session at the Paul Ricard circuit in France, the team suffered nine engine blowups.