On my 1983 300d turbo, I have the 6-blade metal fan. I know they changed the design to the 11 blade plastic fan. Is there a big difference? Less drag? Quieter operation? Less susceptible to failure? Is having the original 6 blade metal fan a sought after part? Should I replace it? My car runs fine, doesn't overheat, but don't know if my engine needs it?

Thanks

There's some marginal improvement to be had by lightening the fan, but these motors rev too low for it to be noticeable. I turned the fan from my old 300CD into a Martha Stewart project:

An idea for all the old 123 Fans out there (literally)