Question

what do you understand by fuel efficiency ​

Answer 1

Answer:

Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work.

Answer 2

Answer:

At its most fundamental, fuel-efficiency refers to the ability of a vehicle to extract energy from fuel. The more energy a vehicle can extract from fuel, the greater fuel-efficiency the vehicle is said to have. Similarly, the less energy a vehicle extracts, the less fuel-efficient the vehicle is.