Answer:
filling petrol in
Step-by-step explanation:
You can improve your gas mileage by filling petrol in your car before you drive.
Mileage indicates a vehicle condition. A vehicle that has covered more miles has less mileage than a less travelled car.
Odometer is a device used to find the distance travelled by the car.
In order to improve the car mileage, keep your gas cap fully sealed and avoid prolonged idling.