Supposedly going faster uses more fuel. But your getting to the place quicker. Shouldn’t you just be using the same amount of fuel as if you were driving slower and getting there later?

Question

Supposedly going faster uses more fuel. But your getting to the place quicker. Shouldn’t you just be using the same amount of fuel as if you were driving slower and getting there later?

In: Chemistry

Answer 1

The formula for drag varies with the SQUARE of your speed.

So, if you are going 10% faster, 1.1 x 1.1 = 1.21

The drag going 10% faster is 20% higher than it was at the slower speed. Assuming all else was equal, you will need to use 21% more energy to go 66 mph than you would 60 mph. To go 75 mph would take (75/60)^2 = 1.56 times the energy needed to go 60 mph.