The 3.0-litre 24-valve inline 6, M 104.98x, was first introduced in 300 SL-24 and 300 E-24, 300 CE-24, and 300 TE-24 in 1989. This engine, fitted to 300 SE/300 SEL, had a very short run in W140; it was replaced by upgraded inline 6 engines introduced in 1993 with two displacements. The smaller 2.8-litre M 104.94x engine was fitted to 300 SE 2.8 (one year only) then S 280 (1994-1998). The larger 3.2-litre M 104.99x engine was fitted to 300 SE/300 SEL (one year only) then S 320 (1994–1998).