Street-Spotted: Mercedes-Benz 300D Sedan

a mercedes diesel parked in front of a house
Street-Spotted: Mercedes-Benz 300DAutoweek

Mercedes-Benz Diesel W123s never die—as the saying goes. They just go into hibernation until the next gas crisis arrives.

Mercedes' diesel lineup actually kicked off before the W123 arrived. The W114/W115 generation offered a diesel model, and so did earlier generations like the Ponton.

The W123 diesel range at its debut offered the previous-gen 2.4-liter, badged as the 240D, but the 300D quickly arrived with a 3.0-liter inline-five underhood with Bosch mechanical fuel injection. This did not make the 300D a track weapon overnight, arriving with 77 hp and 115 lb-ft of torque on tap in 1977, but later models gained quite a bit of power as the Malaise era dragged on.


"The 300D is meanwhile as sharply different from other sedans as it is from other diesels," Mercedes-Benz said at the time. "One factor is a suspension design that would seem entirely at home in a sophisticated sports car: In making this a performance automobile, Mercedes-Benz engineers took 'performance' to mean not only power in a straight line but stability in curves and adhesion even on rough roads."

It also arrived with the mandatory round sealed beams in place of the rectangular European headlights and more generous bumpers, as the DOT knew you'd be bumping into other things in traffic on a weekly basis. (Dammit, how did they know?)

The round sealed beams on the W123 have grown on us, we have to admit, certainly more so than similar setups on other cars like the Peugeot 505 or the Audi 5000 of the late 1970s. Those two are worth a look if you want to recall how bizarre some cars looked with those headlights back then.

But the W123 never gained the rectangular sealed beams that the Volvo 240 received after trying on the round specs, for instance, as entertaining as that would be to imagine today. (We are getting queasy just picturing that).