Petek,
Whoa,,,,that might be it! Frictionall losses WOULD be higher when the "time" was decreased to achieve a set rpm. The "faster" you spin it up, the more it will "resist". Gear weight inertia, friction of the "teeth" losses, gear
oil, all kinds of things would come into play with "time" factored in.
Rule of thumb: 1 pound of rotational weight is worth 3 pounds of static weight. Lighten your tire wheel combination by one pound will have the same effect as lighten the body weight by 3 pounds!
Ernie