Maybe a silly question, but why did the USA get the SD? Also, why not Europe? Never pictured the States as a Diesel-limo loving place..
Because everyone in the US thinks all Mercedes are Diesels... :P :P
I get asked that all the time.
Somewhere I read that Mercedes introduced the 300SD to increase their fleets overall fuel economy due to U.S regulation of automobile fuel economy. Likely in response to the 73' oil embargo and increasing tensions in the middle east/OPEC.
Can't remember where I read it, but if memory serves it was something tax related. Along the lines of averaging out emissions throughout that specific model range, so that they could continue selling cars in California and other similarly restrictive states. Which is also why the US petrol models are using low-comp engines, and are loaded with all the useless emissions gizmos. It continued with the W126 300SD and 350SD, until the EURO 1 emissions norm was introduced in 1992(ish). Of course, this could be a load of nonsense :)
p.s.: Looks like I'm not the only person that recalls reading about this.
Fun fact, the 1978 300SD was the first turbodiesel passenger car sold in the United States.
In German. Something about Jimmy Carter and regulations.
(https://www.benzworld.org/attachments/300sd-001-jpg.510034/)
(https://www.benzworld.org/attachments/300sd2-001-jpg.510035/)
Guess it wasn't such a silly question after all! :D