Of course a bicycle that is what... 1.2x human weight... is more efficient than a car that is probably ~10x human weight, when you measure it by vehicle rather than kcal per mass.
The weight of a car is not optional. If I want to move some mass between point a and point b, and I do it by car, I have no choice but to haul along that extra ~10x my weight. Measuring by kcal/mass ignores this practical reality in favour of a more precise definition of "efficiency".
Also if you're riding a bike that weights 1.2x your body weight, you have the wrong bike! Good god!
Don't know if you were kidding but I think the implication was the combined mass was 1.2x your weight. Of course even then, that's still a pretty heavy bike (I think my commuter clocks in at about 10% of my weight)
Also if you're riding a bike that weights 1.2x your body weight, you have the wrong bike! Good god!