The 126 C4 stood no chance against the dominant McLaren MP4/2 in 1984 and won only once: Michele Alboreto triumphed at the Belgian Grand Prix in Zolder, where he also claimed the team's only pole position of the season. Ferrari finished second in the Constructors' Championship, 86 points behind McLaren. The engine produced around 850 bhp in qualifying, but the car lacked downforce; the drivers complained of a lack of grip and ran high wing angles. This cost straight-line speed: in South Africa, the Ferraris were about 25 km/h slower than the BMW-Brabhams on the long straight.
Summarized from the sources cited below; every figure in the text was automatically verified against the sources.
Learn morePlenty of engine, little downforce · The fuel problem · Season summary
Plenty of engine, little downforce
With roughly 850 bhp in qualifying, the Ferrari turbo was virtually on par with the powerplants from BMW, Renault, and Honda. However, the car itself generated little downforce. Alboreto and Arnoux complained of poor grip throughout the entire season, and at circuits like Kyalami, Hockenheim, and Monza, top speed suffered because they had to run as much wing as possible.
The fuel problem
Steep wing angles increased drag and consequently fuel consumption. Because refueling was prohibited in 1984 and only 220 liters were permitted per race, both drivers often had to lap slower than they were capable of just to reach the finish.
Season summary
In the Constructors' Championship, Ferrari finished 86 points behind McLaren, but 10 points ahead of Lotus-Renault. Across its lifespan, the entire 126C series won 10 races, took 10 pole positions, and collected 260.5 points. Alboreto took the sole victory of the season at Zolder, where he also scored the team's only pole position of the year.
Summarized from the cited sources; every figure was automatically verified against the sources.