Q: Q: Bad gas mileage

asked by on

My truck has been getting low gas mileage lately. About a year ago, it was around 15 MPG and now it dropped to 8 MPG. I understand that it is a truck and needs a lot of gas, but this is very poor gas mileage. I've done some checkups and everything seems fine. The catalytic converter is ruled out as a cause. I had the intake cleaned; spark plugs replaced; wires checked; new air filter installed; switched to Shell gas. What could be causing such bad gas mileage?

Hello there. A decrease in fuel milage can be attributed to a few different faults. The most common causes are leaking fuel injectors, oxygen sensors, coolant temperature sensors, vacuum leaks or exhaust leaks. A qualified technician, such as one from YourMechanic, will check all of these for proper operation and can make any repairs required.

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. Q: Bad gas mileage

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: Problems putting in a spark plug in I had to thread the port for the plug now it won't stay in

You are supposed to thread the hole out and get all the material from cutting cleaned out of the hole and engine cylinder. After it is cleaned then you should clean the threads with brake cleaner that will dry quickly....

Q: Have possibly been driving for a year without an air filter

I personally do not like the aftermarket oil bath type of air filters with vehicles that have a mass air flow sensor. The oil that comes through the filter can contaminate the mass air sensor which would require regular cleaning...

Q: Noise from right rear wheel area when turning right at low speed.

Hey there. You may be hearing the backing plate behind the rotor rubbing on the rotor due to it being bent too close to the rotor or the bearing having excessive play and letting the rotor get too close on...

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 to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
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...