How much will adding 16 lb to my car affect ET/mph(rotating weight)

toolmanmike said
I thought reciprocating Wright was connected to the crank. Your wheels are unsprung weight.

It's rotating weight,..... so it adds 16 lb to the weight of car but also adds 16 pound of unsprung Weight that the eng has to push or drive.
un and sprung weight i get confused on so i may have them backwards.