The loweest mileage I've gotten is 11 mpg in the dead of winter (0-10 degrees F every morning) in 100% city driving. The best I've gotten was 23 mpg on a 2 day highway trip last summer. My last tank, which was 60% city driving and 40% highway (roughly) got me 16 mpg and it is still pretty cold. Obviously not the best mileage, but not the worst by any means.
1995 E420 - retired
1986 420SEL - retired