Q: Fuel inefficiencies

asked by on December 13, 2017

I seem to be going through gas like it's water. After filling up, I begin to see the needle go down only after 20 miles of driving. It used to be over 50 miles before the needle went down. What's causing fuel inefficiency?

My car has 114500 miles.
My car has an automatic transmission.

In order to check your fuel economy you will need to fill your fuel tank completely and zero your trip meter and drive vehicle until you use at least a half tank of fuel and then fill the tank and take the miles driven and divide the gallons it took to fill it up to get the mileage per gallon you got. This will be your combination miles per gallon between city and highway. If you did not get more than about 16 miles per gallon then have your computer tested for stored codes and check data for O2 sensor performance to see if you may have problems. You should check to make sure you have a clean air filter and tune up if not done before recently. Have a mechanic like one from YourMechanic check the systems for you if no noticeable problem was found with low fuel mileage. You may have a mass air flow sensor that needs cleaned or problems with variable intake manifold.

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