[M_a_t_t]

The taller the tire the less rolling resistance (of course everything being the same). There are many factors when it comes to rolling resistance of tires so it is hard to say for sure if that would count.

Typically you would want a taller tire for better fuel economy (less rpm). Is it hilly enough in your area to make smaller tires worth it since their only benefit is on hills when you need to speed up? The rest of the time you will be at higher rpms for the trip.