My econobox M43 engine gets me about 12 km/liter = 28.2 miles/gallon(US) in city driving.
We have 95 RON petrol if that makes a difference...
Just for reference my previous car (94 jdm WRX) gets me on average 9.2 km/liter = 21.6 miles/gallon(US). On the standard engine program it has twice the power of my E36 (~220hp) and I used it a lot, heh... (who cares if it's an auto)