Fabi drove for Benetton Formula in the No. 19 Benetton B186-BMW M12 after Toleman were fully taken over before the 1986 season to become Benetton, with powerful ( qualifying) engines, and talented young Austrian Gerhard Berger joining. The Benetton was fast but fragile with difficult Pirelli tyres and Fabi often qualified better than he raced. He managed pole position at the Austrian Grand Prix and the Italian Grand Prix but his best finish was fifth at the Spanish Grand Prix. He gain a reputation for being most competitive on faster circuits and struggling on slower, more technical courses. Both pole positions were at the two fastest circuits on the 1986 calendar, the Österreichring and the Autodromo Nazionale Monza. He ended the season fifteenth in points.