Any one worked out ways to max mpg on motronic cars?

I have a BMW 533i ( 84 ). With fuel prices rising the issue of scrapping is coming up. Also the Volvo 740tds seem to "suck" , why? 2.4 ltr 4, ratios and weight aren't that bad, can she be improved? David Vizard had afew chapters on max economy for early minis. Anyone set up a motronic car with 15:1 cr etc?