The 425, which gradually abandoned the name Biturbo in view of the reliability problems of the original, was the first 4-door version of the Biturbo series, in 1984.

The design remains identical although it incorporates the rear doors and consists of a maximum of parts of the two-door version.

As its name suggests, the displacement has increased to 2.5l and gains in power and torque, making it a comfortable wagon coupled with a racy and nervous car.