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

First of all, you don’t need any fuel to keep your vehicle at certain speed. You need fuel to gain acceleration. You use acceleration to get your car to a certain speed. If you travel with your car on earth, there are a lot of things, which try to slow down your car, such as friction or air. You also need acceleration to surpass the opposing forces. These forces can be generalized, so that you can calculate the required acceleration, which allows you to stay at the same speed.

Car engine is a complicated thing. Engines are designed to be the most efficient at certain acceleration or speed for each gear. You wouldn’t want to go in details, but know, that things that you wouldn’t imagine are taken into account (such as the proportion of oxygen to other gases in atmosphere) in order to calculate the designed efficiency. With that said, to be the most efficient, you need to use the most efficient speed at the most efficient gear (which usually is the highest gear). Going too slow, or too fast is inefficient by design.