Here's my two cents' worth:
The recent response that talked about rotational inertia makes sense to me
(a mechanical engineer). You may also want to consider, regardless of that,
"pretending", temporarily, that the wheel isn't rotating while you travel at
speed. Ignoring rotational inertia and rotational acceleration, the lighter
tire will be easier to accelerate in a straight path, say, from a standstill
to any given speed, compared to the heavier tire. Remember F=ma?
In addition, the shorter tire may allow the vehicle body to be less tall and
therefore more aerodynamic.
Tallguy