sentences:  In testing it proved far faster than the 312T5 chassis the team were then using and Gilles Villeneuve preferred it, though he had reservations about the handling.Early unreliability of the turbo engine put paid to Villeneuve's championship hopes but he did score back to back victories in Monaco and Spain, as well as several podium places.Because of the problematic handling the 126CK was at its best on fast tracks with long straights such as Hockenheim, Monza and Buenos Aires.