I guess I'm unusual in that I look at % over EPA as much if not more than the actual mpg for comparison of cars/mods. your metro averaging 11% lower than epa which is terrible even though you're getting 12 mpg better than my truck with is a few % over the EPA est.
1991 Toyota Pickup 22R-E 2.4 I4/5 speed
1990 Toyota Cressida 7M-GE 3.0 I6/5-speed manual
mechanic, carpenter, stagehand, rigger, and know-it-all smartass
"You don't get to judge me for how I fix what you break"
40 mpg is exemplary for the super charged Buick.... not quite as spectacular for a 1 liter Suzuklone.
I prefer to think of the percentage increase over a 'standardized' EPA number is of more importance than an outright number, HOWEVER...
There are some (like me) that have made drastic changes to a factory vehicle to make it.. well... a factory vehicle. My EPA numbers for my wagon are based on the gasoline V6 engine installed in my car when it left the factory, not the numbers based on the same car if it had come with the other, more fuel efficient optional factory installed TDI diesel engine. My Jetta was built with the TDI diesel so it has the diesel's EPA number as a reference. That one'll never get into top percentage billing while I drive it.
Buy a Mustang GT 500 and pop in the Ford V6 for instant top percentage standings.