上斜與平路用油比較

It is really difficulty to calculate how much fuel is consumpted more. I think it is related to :
1. The weight of the car because it increases the potential energy of the car.
2. Efficiency of the car at flat surface and 20 degree slope.
3. Heat value of the fuel.

好似無答過個問題

if using the same speed and same distance, of course while a car climbing a 20 degree slope is more fuel consumpted than going in a flat surface.