[nl]

This isn't right. The difference in weight of a tire in the same class is insignificant (~400g) compared to the bike (~7kg) and the rider.

Indeed based on your explanation the stiffness of the tread is going to be as much of a cause as anything.

[matsemann]

There can be some merit to the fact that the weight in a tire is rotating mass, though. But then you get into thoughts about that the bottom of the tire is technically standing still, and the top of the tire is double the speed of your travel. And does it then matter?

[ActorNightly]

Its a very rough rule, and has exceptions, but its generally works out.

Compare continental gatorskins in 28c vs continental gp5000 in 28c. Gatorskins have more casing to prevent puncture, so they are heavier, but that casing also takes away from the rolling efficiency.