OM403

From January 1972 West Germany's minimum-power rule of 8 PS per tonne was to apply to trucks and road trains above 28.5 tonnes, which meant 304 PS for a 38-tonne combination — beyond any naturally aspirated engine Daimler-Benz then had. The V10 shown at the 1969 Frankfurt show answered that. At 15.95 liters it made 320 PS and 1,010 N·m, burned 223 g/kWh at rated power for a thermal efficiency of about 0.39, and weighed 910 kg dry, which for a ten-cylinder of that size was a genuinely remarkable figure at the time.

It topped the New Generation range in the 1632, 2232 and 2632, and was the largest of the three engines offered in the 1974 O 303 coach until a facelift dropped it in favor of a turbocharged V8. Its other life was military. The multifuel OM 403 VA was developed so that an army engine could share as many parts as possible with a mass-produced commercial one; turbocharged as the OM 403 A it gave 390 PS in the Spähpanzer Luchs, the amphibious 8×8 reconnaissance vehicle drawn up by Porsche on contract to Daimler-Benz. 408 were delivered between 1975 and 1977.