thumb|285x285px|An [[egg being cooked on a 3.0 L M103 engine]]
The Mercedes-Benz M103 was a 15-degree, straight-6 crossflow cylinder head automobile in production from 1984 to 1997. It is a single overhead cam design with 2 valves per cylinder. The M103 was replaced by the M104 starting in 1989. This engine received several updates over the years of production, one of the updates was a change from a "heart shaped" to a "HEMI" spherical combustion chamber.
Specifications
The only mechanical differences from the M103 3.0 L to the M103 2.6 L were the smaller bore and intake valves, with a slightly different airbox. The CIS-E components between 2.6 and 3.0 variants are all shared for any given model year with the exception of the ECU making engine swaps from 2.6 to 3.0 virtually bolt-in.
{|class=wikitable style="text-align:center"
! Model
! 260
! 300
|-
! Type
! 103.940
! 103.980
|-
| Production period
| colspan=2 | 1984–1997
|-
| Cylinder bore
|
|-
| Displacement
|
|
| 179 PS (176 HP)