Question

In order to make vehicles more energy efficient, what can be done?

Answer 1

Hi! The efficiency is the work done per the work required.\[\frac{W_{done}}{W_{required}}\]That's like, how much energy do you put towards what you want, versus how much energy you actually used.

Engines use explosions to move parts to rotate the wheels.
Now, the energy came from the explosion.
That energy was in the form of \(\sf{sound,\ light,\ heat,\ and\ motion}\). But all you wanted, all that you calculated as the work, was the \(\sf{motion}\). So, the work done was less than the energy that you put in.

Answer 2

There exists a theoretical limited based on the working temperatures of heat engines such as the ones that run in cars... to reduce this loss you need to increase the temperature difference between working temperature.

This is related to entropy.