No.

There is not less weight to accelerate and deccelerate, there's less mass for the springs/dampers to have to deal with, which means the suspension can cope with what the road throws at it more efficiently.

I myself binned the 16s years ago. I understand that there's minor differences in how it feels, but I'm not Tony Hunter so can't say I've really noticed any difference, other than on my wallet.

It's both actually. For anyone that cares....

The laws of physics rule here. Energy is needed to bring the wheel/tire mass up to speed (mph) and to spin it to the related rpm. Consider a lighter tire/wheel combo:

m = mass reduction

I = inertia reduction

w = rotational speed

v = car speed

r = tire radius

E = total energy saved by mass reduction "m"

^2 = squared

E = 1/2 m v^2 + 1/2 I w^2

E = E(speed) + E(rotation)

Rotary Inertia is the sum of each bit of mass times it's radius squared. If all the mass reduction is at the tire OD (the theoretical but not practical limit), the inertia reduction is the maximum possible value:

I = r^2 m

The relation between car speed and tire rpm:

v = r w

Combine 3 equations above:

E = 1/2 m v^2 + 1/2 (r^2 m) (v/r)^2

E = 1/2 m v^2 + 1/2 (m) (v)^2

E = 2 x E(speed) ... the 2X limit

So if you drop 10 lbs per corner, the net total weight savings is 4 x 17 = 68 lbs. For a 3700 lb car and driver, that's only a 1.8% change.

The main benefit of reducing wheel/tire or any unsprung weight is handling and comfort, by increasing the tires ability to keep good contact with the road. Total unsprung weight might be 80 lbs per corner, and 10 lbs would be a 13% change ... very significant.