Hoshy,
My daily share car is a e36 325td, my mate gets 40+mpgs and it rides great.
Make sure you have the bosch fuel pump, it's the daddy, it'll do all the "alternative" fuels
These TD lumps are self fueling so you just need to wind up the boost some more and keep an eye on the AFRS, something YOU could do with your many talents.
IIRC the TD can be tuned to about 160bhp and the TDS over 200bhp but not many about running that all day.
I wound up a Ford escort TD the other day for a mate, it wouldn't go over 95mph beforehand, now sees 110+!
Fozz