924S 2.5L 1988

By 1988, the final year of production for the 924S, power increased to 158 PS (116 kW; 156 bhp), matching that of the previous year's Le Mans specification cars and the base model 944 (itself detuned by 3 PS (2 kW; 3 bhp) for 1988). This boost was achieved by utilizing different pistons, which raised the S' compression ratio from 9.7:1 to 10.2:1, resulting in an increase in the octane rating from 91 RON to 95.

Consequently, the 924S became slightly faster than the base 944 due to its lighter weight and more aerodynamic body. The 1988 model also saw the addition of three-point safety belts in the rear seats.