OM67

The Reichswehr had written a specification — a three-axle cross-country lorry of three tonnes payload, high ground clearance, twin driven rear axles — and by 1934 Daimler-Benz had answered it with the LG 3000. Under the bonnet sat the OM 67: an unsupercharged in-line six with pre-chamber injection, pressure-circulation lubrication and water cooling, rated 95 PS at 2,000 rpm, with three separate cylinder heads and, usefully for an army, the ability to run on crude oil. Around 7,500 LG 3000s were built to 1938, making it with the Henschel 33 the most numerous diesel three-axle truck the Wehrmacht had.

The engine was reworked continuously. From 1937 the OM 67/3 changed the bore-stroke proportions to 105 × 140 mm, put the crankshaft on seven main bearings instead of four and cut the cylinder heads from three to two; the OM 67/4 of 1939 reached 112 PS, the OM 67/8 120 PS. Not all of it went to war — some LG 3000 chassis were bodied as buses and worked Reichspost routes in the high mountains. After 1945 the L 4500 restarted with the pre-war OM 67/4, and in 1954 the same engine was simply redesignated OM 325, becoming the root of the large OM 300 truck family that carried Daimler-Benz through the Wirtschaftswunder.