My opinion: Most of the Diesel Board members drive W123s (I'm surmising). Of that subset, there are several other "extreme" subsets, like extreme modifiers (manual transmission swap-ins and intercooler installations), concours fanatics, or SVO/WVO/Biodiesel geeks.

Fuel geeks are few and far between. Most people just want good quality DIESEL, and don't want to fuss with homebrews.

But if anyone wants further information on Bio, check my compilation of links.