Zzr600
 

My 1993 zzr 600 averages 4.0l/100 with just gear changing.

I had a zx600e as they were know in the states, of the 5-7 bikes I've owned one of the smoothest motors, 2 bad 2nd gear didin't work. Never actually tracked it's mileage but seemed all the rest at 45 mpg.