[bhazard]

A higher numerical final drive (its actually 'lower' or 'shorter' gearing) means higher rpms at any speed. You'll have better acceleration and a lower top speed. City mpg could even go up, but highway mpg may go down.

A lower numerical final drive (which is 'higher' or 'taller' gearing) gives you lower rpms at any speed. Pretty much the opposite of shorter gearing. Highway mpg should go up, city mpg depends, you may end up lugging your engine more.