wow, I feel better now.
My '06 325xi is doing ok. I average 21 with city driving and on a recent 6 hour trip on the interstate, I averaged 29mpg and my avg speed was 80+ MPH with short bursts up to 100+ (had marked police car in front and marked police car behind).
another recent 2 hour trip driving at 65mph, i averaged 31 mpgs.