I have a 1990 765 Ti...I get bad gas mileage...but wait there's more. Itseems that I get about 140 iles to the first half tank...the second half drains...I only get about 80 miles from the middle point of the gage to E...If I fill up a half empty tank, I'm getting close (not quite) 20 mpg...if I let it get near Empty I'm looking at about 14 mpg.
I've checked several times and unless someone has a clue for me to investigate, I'll just keep filling up around half empty.