Calculate Your Own Gas Mileage

You need to learn how to calculate your own gas mileage. Don't take anyone's word for it. Especially, do not rely on the manufacturer's estimate. This is a number that is used to sell cars, not to save gas. They use professional drivers on closed courses. You will never get the same gas mileage unless you are coasting down a hill. Use the manufacturer's number to compare different models of cars, but don't think it will help you determine how much gas you will end up putting in your car.

The Simple Gas Mileage Test

The first thing you need to do is drive until your tank is empty. When you get low, just drive near a gas station until the low fuel indicator has been on for some time, and you are quite sure there are just a few drops left. If you do not have a dashboard indicator which tells you how many miles you have left, make sure to bring a full gas can in case you run out on the road. When your tank is empty, fill it up and write down the number of gallons your tank holds.

How to Calculate Gas Mileage

Now, reset your trip odometer and drive normally. Obey all speed limits and do not load the car with anything that you don't always take with you. If you normally drive by yourself, do not drive with other people in the car. Avoid any routes that you do not usually take, especially up hills. When your tank is empty again, note how many miles you have driven. Divide the miles you have driven by the number of gallons that your tank holds and you will have your baseline gas.

Greater Accuracy in Gas Mileage Calculation

What you have is good, but you can get an even better reading. All sorts of variations affect your gas mileage. The weather, the routes you drive, your mood (the calmer you are, the less likely you are to accelerate and brake too much) can impact your mileage. To make sure you have the best possible reading, perform the test a few times. Then take all the results, add them together and divide by the total number of tests. This is your standard average gas mileage.

Try Driving Differently to Test Gas Mileage

Now, to see how driving fast really uses up so much more gas, do a gas mileage test when you are driving very fast. Note your average speeds. You will find that your mileage is much worse than the standard baseline result you achieved earlier. The same will hold true for hilly drives. Now that you have an accurate baseline, you can test all sorts of driving styles and routes against the baseline. Make sure to also note the key points of the weather: temperature, humidity, precipitation, etc. You will find that the more moisture that is in the air, the worse your gas mileage will be.