While the B188 was still competitive enough to compete for podium places, the limit of the car and its older engine (which was now in use by other Ford-Cosworth powered teams) had been reached and Benetton was beginning to lag behind the V10 McLaren-Hondas and Williams-Renaults as well as the V12 Ferraris.
The B189 finally appeared at the French Grand Prix where Nannini showed the potential of both the car and the new Ford engine by qualifying 4th ahead of both the Williams-Renaults and the Ferrari of Gerhard Berger.
Pirro, at the track where he was based as the McLaren test driver, used the development engine in the race and moved quickly from his 22nd starting spot to 10th by lap 33 before being forced out due to a crash with the Dallara of fellow Italian Andrea de Cesaris at the hairpin.
The car was again driven by Alessandro Nannini who was joined at Benetton by three time World Drivers' Champion Nelson Piquet.
The B189B was the last Benetton to use the distinctive air intakes on either side of the cockpit with the B190 having a single airbox in the now standard position above the drivers head.