Unfortunately, once the European races started the problem surfaced of the front tyres taking a long time to reach working temperature (much longer than the Goodyears) which caused severe understeer, a situation was not helped by the unseasonably cool European summer or the lack of weight at the front of the car.

The team's second driver Marc Surer recorded the season's fastest speed trap time during qualifying at Paul Ricard when the turbocharged BMW engine pushed the BT54 to 335 km/h (208 mph) on the 1.8 km (1.1 mi) long Mistral Straight.

This speed was almost emulated at Kyalami for the South African Grand Prix when both Piquet and Surer were trapped at 332 km/h (206 mph) on the circuits 1.65 km (1 mi) long front straight.

At the European Grand Prix at Brands Hatch, Piquet qualified a strong 2nd, but on lap 7 drove into Keke Rosberg who had spun his Williams while challenging Ayrton Senna's Lotus for the lead at Surtees (with nowhere to go and no time to react, Piquet hit the Williams, taking off the BT54's nose cone and badly damaging the front left wheel and suspension).

The BT54 was replaced for the 1986 season by the Brabham BT55, although the team did use the BT54 for the 1986 British Grand Prix at Brands Hatch after the lack of results from the radical lowline BT55.