The first energy crisis impacted Detroit drastically more than the imports, which were mostly poised to capitalize on it, given their generally small and efficient cars. But there were some big exceptions, like the Mercedes S Class. Their superb new W116 line had arrived just a few years earlier with a substantially larger and heavier body. And emission controls had clipped the once free-breathing Mercedes sixes. So the W116 arrived in the US in strictly V8 form, as the 450SE/SEL. But its 13 mpg fuel economy was a bit excessive in the light of the post-crisis outlook, so Mercedes offered the 280S as a cheaper and more efficient alternative. The result was decidedly underwhelming, since the emission-controlled DOHC six made a mere 120 hp, and the big Benz weighed almost 4000 lbs, resulting in a 0-60 time of 16.3 seconds. And fuel economy was only modestly improved. Mercedes would eventually find a better solution than this.
The mediocre performance and efficiency of the 280S is what give Mercedes the impetus to put its turbo-diesel engine in the S Class in 1979 (300SD), for the US market only. Performance was not much different, but fuel economy was drastically improved, solidly in the mid-20s range. It was a decidedly better compromise than the 280S. And already in 1977, this engine was replaced by the fuel-injected version, making 142 hp, which brought back some of the pep that the European versions had.