bro, can you please clarify your city driving & hiway driving. kc if ur referring to baguio as ur city driving, then tama lang consumption mo. now kung yung hiway driving mo naman refers to mac arthuron a day time, pwede na yan kc halos stop & go rin dyan. sa dami ng motor, tricycle & kuliglig halos panay ang bwelo pag overtake. try measuring it sa sctex-nlex then it should give you a much better FC.

As said many times, FC is very dependent to so many conditions. check out first the basics before you remeasure ur FC.