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. The car proved to be very fast but Gilles Villeneuve found the handling to be very difficult, calling the car "a big red Cadillac". According to Villeneuve's teammate Didier Pironi and English engineer Harvey Postlethwaite, who arrived at Ferrari well into the 1981 season, it was not the chassis that was the main cause of the car's handling problems, but the very bad aerodynamics of the car. Postlethwaite later said that the 126CK "had a quarter of the downforce that the Williams or Brabham had that year". The poor aerodynamics of the car, coupled to the chassis' hard suspension (all teams in 1981 were running with hard suspensions to increase aerodynamic efficiency), created a tendency to make the car slide into corners before the ground effect pulled the car back on to the track. This had the undesired effects of exposing the drivers to even larger g-forces than the Williams FW07 or Brabham BT49 and making the car tend to overuse its tyres. The engine had massive turbo lag, followed by a steep power curve, and this upset the balance of the chassis. Although the Ferrari engine was the most powerful engine that year, even more so than the Renault - the combination of a severe lack of downforce and an abruptly powerful engine made the car an annoying menace to race against. At the Österreichring one gaggle of 6 naturally aspirated, better handling cars formed behind Didier Pironi for a number of laps, followed by three other cars shortly afterwards: none of them, however, could find their way past easily due to the Ferrari's power advantage on the very fast Austrian circuit, even though the car was very clearly slower going through the Austrian circuit's fast, sweeping corners. The same thing also happened at Jarama that year; 4 cars were stuck behind Villeneuve on the tight and twisty circuit, but he was able to hold off the cars behind him thanks to the car's power advantage and fair mechanical grip. Monaco and (less so) Jarama were slow circuits where aerodynamic downforce was not as important as mechanical grip, so combined with Villeneuve's famed ability