Skip the auto shop - Our mechanics make house calls

Q: low gas mileage

asked by on

My GMC has been extremely low on gas mileage. I drove to pick up my brother about 5 to 7 miles away, and I had 2 quarters of a tank of gas – a half a tank when I left the house. When I got to my brother’s house I had only a quarter of a tank left. It’s been eating gas like crazy after I got my oil change. I put 5 quarts of oil in, and I still needed to put in two more quarts. I haven’t done that yet. I made the mistake of getting an air filter instead of an oil filter. I had the fuel injectors cleaned last July. Do you have any suggestions that will help me fix this problem?

Decreases in fuel economy are caused by things like fuel control issues (fuel injector leaks, bad O2 or other sensors), transmission problems (won’t shift into high gear, slipping, torque convertor clutch fails to lock-up), misfires (ignition related), low tire pressure, or dragging brake calipers. I recommend having a trained professional inspect your car in order to determine why it is getting worse gas mileage. From there, they will be able to help you move forward with any repairs needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

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 to fix gear shifter

In many cases, this problem can be caused by a loose connection behind the instrument cluster. First, the fuses for the gear and information center displays must be checked. If the fuse did blow, there is a faulty component along...

Q: What is the best oil to use?

Hi there. If your engine is consuming too much oil, then I would consider checking the (PCV) Positive Crankcase Vent Valve and see if its plugged up. A PCV valve can plug up causing the engine crankcase to over pressurize...

Q: I got oil changed n they told me I had metal in oil n two major oil leaks I got the car sept 24 from jd by rider of Greenville bk

Hello. Metal shavings or pieces in the oil pan can be a serious sign of major mechanic failure on the horizon. Did you personally see the metal shavings? Do you trust that this was an honest diagnosis? If so then...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.