"What kind of gas mileage do the smaller engined cars get?"
28-30 mpg
What mileage does a 2110 get?
26-30 mpg (depends on how much you put your foot into it)
Also how much performance do you lose in say 0-60?
1600cc versus a 2110: About 4-5 car lengths.
60-75 mph?: 2 car lengths
75-85 mph and higher? Many, many car lengths.