M104

The M104 arrived in 1989 above the M103 rather than in place of it: twin overhead camshafts, 24 valves, variable intake timing, cylinder-specific ignition timing and jets spraying oil at the underside of the pistons, first in the 300 E-24, 300 CE-24 and the 300 SL-24. From 1992 it took over the whole range — a 2.8 to replace the single-cam sixes, and a 3.2 to replace the 3.0 so that the same performance arrived at lower engine speeds in the S 320, E 320, SL 320 and G 320.

AMG went further with it. The 3.4 of 1990 was a bored and stroked three-liter; the 3.6 behind the C 36 and E 36 AMG opened the 2.8 block by 2.1 mm and used a heavily reworked crankshaft from the 3.5-liter OM 603 diesel to find 18.9 mm more throw, for 280 PS. One M104 was not an M104 at all: needing a compact six for the V-Class, Mercedes-Benz bought Volkswagen VR6s half-finished and designated them M104.900. The M112 V6 began replacing the family in 1997.