1984-87 McLaren TAG-Porsche
Prost lost the championship to Nelson Piquet of Brabham by a mere 2 points in 1983. He believed that his Renault side was not developing the car and that it was not his fault that his points tally was overhauled in the final races by Piquet.
Renault fired him for his outburst and he immediately re-signed with McLaren who had Ron Dennis at the helm having merged with his Project Four. McLaren, now driving with the TAG engines, easily took the constructor's championship, but Prost lost to teammate Niki Lauda by just half a point in 1984.
1985 saw him win his first world title comfortably and Lauda retired. Prost was joined by world champion Keke Rosberg for 1986, and he defended his title taking advantage of the Williams-Honda of Nigel Mansell and Nelson Piquet taking points off each other - in the end by just 2 points. Next year, the Williams Honda won both titles and McLaren decide to switch to Honda engines for 1988.