The more aware you are of the amount of fuel that you use, the more you can do to try to reduce your gas costs. If you notice that your gas efficiency is decreasing, it could be an indicating factor that your car needs servicing.
Make weekly comparisons with your fuel log that you keep in you car to see how much your gas consumption is going up and your mileage per gallon is going down. If you are finding that you are constantly seeing less and less performance from your car and spending more for gas at the fuel pump, then you’ll know that you need to take action so that you can start seeing a savings in your gas economy rather than a constant deficit.