1. Air Filter

Do you know about Carnot-engine? Don’t feel strange, it is the same ignition engine deployed in your car, and the reverse application of its principles provides the environment control system in your automobiles. You are on your own to study the detailed process, but in a nutshell, engine heats up a lot during the drive and needs good thermal regulation, which is achieved through air filter.

Since it is directly affecting performance of the engine, replacing air filter alone can improve the mileage. Dusty or air-blocked filters restrain flow of the wind to the engine which results in increased fuel consumption.