* Air resistance: As your car moves through the air, it creates a pocket of air resistance, or drag. This drag increases with the square of your car's speed. So, if you double your speed, you will experience four times more drag.
* Rolling resistance: Rolling resistance is the resistance created by your tires as they roll over the road surface. This resistance also increases with speed, but at a slower rate than air resistance.
* Engine inefficiency: As your car's engine works harder to overcome air resistance and rolling resistance, it becomes less efficient. This means that it uses more fuel for the same amount of power.
* Transmission losses: At higher speeds, your transmission loses more energy through friction. This is because the gears are spinning faster and there is more contact between the gears.
All of these factors contribute to the decrease in mileage that you experience when driving at higher speeds.
