Q: Fuel inefficiencies

asked by on

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.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Fuel inefficiencies

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: How much to repair an electronic steering lock 2009 c300

You may be right that your car needs a new electronic steering lock (ESL) but there could be other issues as well. There is a digital conversation that takes place among the modules of your car before the decision to...

Q: Rattling sound under the car.

Hi there. If you have a flex plate or a flywheel on your vehicle, the nose could be a loose bolt causing the rattling noise as the engine is running. If the noise lessens out as the engine is revved...

Q: What is the anti-scan feature on the keyless entry keypad?

While the keyless entry keypad on the driver door of your car provides another way to lock and unlock the doors and even open the rear glass, it’s also a weak point in the car’s security. To provide better protection,...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...