The OM603 engine was a straight-6

Straight engine

Usually found in four- and six-cylinder configurations, the straight engine, or inline engine is an internal-combustion engine with all cylinders aligned in one row, with no offset...

 Diesel

Diesel engine

A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...

 automobile engine from Mercedes-Benz

Mercedes-Benz

Mercedes-Benz is a German manufacturer of automobiles, buses, coaches, and trucks. Mercedes-Benz is a division of its parent company, Daimler AG...

 used from 1984 through 1999. The 603 saw limited use in the W124

Mercedes-Benz W124

W124 is the Mercedes-Benz internal chassis-designation for the 1985 to 1995 version of the Mercedes-Benz E-Class. The W124 models replaced the W123 models after 1985 and were superseded by the W210 E-Class after 1995.-History:...

, W126

Mercedes-Benz W126

The Mercedes-Benz W126 is a series of flagship vehicles manufactured by German automotive marque Mercedes-Benz. Premiering in September 1979 as the successor to the earlier W116 line, the W126 was the second generation of the Mercedes-Benz flagship to officially bear the S-Class name referring to...

 and W140

Mercedes-Benz W140

The Mercedes-Benz W140 was a series of flagship vehicles manufactured by the German automotive company Mercedes-Benz. The car premiered at the Geneva Motor Show in March 1991, with the first examples rolling off the production line on August 6, 1991. Short and long wheelbase sedans were offered...

model vehicles.

The 603 engine has a capacity of 2996cc and was an engineering marvel in pre-chamber design and a technological leap forward from the "tractor motor" 5 cylinder OM617. Versions 603.96x and 603.97x are turbocharged. Only turbocharged models of the 603 series were available to the U.S.