If you want to test the accuracy of your meter or want to get the most accurate reading of your car¡¯s gas mileage, you can manually calculate your vehicles miles per gallon yourself. Or perhaps you¡¯re driving an older car that doesn¡¯t have a fuel economy gauge and you¡¯d like to know just how much gas you¡¯re getting for your buck.
To calculate your own fuel economy, grab your car keys and a handy notebook and head out to the local gas station. Make a note of the price you are paying for gas in your book and then fill your tank all the way.
While the tank is filling, record the mileage on your odometer in the notebook. If your car is equipped with a trip odometer, zero it out. Then drive your car as you normally would, until the gas gauge reads a half of a tank. Then fill your tank again at the same gas station as the first time and try to use the same pump to assure that you¡¯re getting the most accurate measurements. Record in your book how many gallons it takes to fill your tank. This reading will be on the gas pump above or below the total price you¡¯re paying for the fill up.
Take out your notebook again and record your mileage. Subtract your mileage reading after the first fill up from your current mileage. This number should be the same as the number on your trip odometer, which you can use as a backup. This number represents how many miles you drove since your last fill up. Divide this number by the number of gallons it took to fill your tank, and the result is your car¡¯s miles per gallon.
The higher this number is, the better your gas mileage is and the more money you¡¯re saving. Do this calculation a few more times to get your car¡¯s average miles per gallon and a better idea of your actual gas mileage over the course of a few weeks or a month. The type of driving you do (city or highway) will change your MPG readings. City driving lowers your fuel economy and highway driving gives you better gas mileage.
Other factors affect your gas mileage as well, such as how aggressively you drive your vehicle. Quick starts and stops negatively affect your gas mileage. Auto maintenance issues like taking your car in for regular tune ups, along with using the manufacturers recommended grade of oil in your car and keeping your vehicles tires properly inflated will positively affect your gas mileage. Driving the proper speed limit and using your car¡¯s cruise control to maintain constant speed on the highway all increase your gas mileage too. By tracking your gas mileage you can develop habits to increase fuel economy with better driving habits.
