Skip the auto shop - Our mechanics make house calls

Q: What is causing the massive loss in mpg?

asked by on

I own a 2010 Chevy Cobalt, 2.2l Ecotec 5 speed manual. Bought it used with 73k miles on it. I've been driving highway since Monday on a full tank of gas, reset my mpg average. The car is rated 37 highway, and my on board dash mpg average is at 31 mpg. The car is running fine, a tune up might be due but that couldn't possible cause a 5+ mpg loss. Any suggestions? Ran my code reader and nothing coming up or stored, car. Seems to be running just fine. No issues anywhere

My car has 73000 miles.
My car has a manual transmission.

A: Hi, thanks for writing in. A tune up can de...

Hi, thanks for writing in. A tune up can definitely cost several miles per gallon, depending on how badly it needs the tune up. There are several factors that go into fuel mileage: how much actual city driving there is, highway speed has a huge effect, what rpm you shift at, and even the quality of the gasoline being used. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this gas mileage issue for you, and make or suggest any repairs as 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 much for an oil change, battery change and alignment cost?

Billing question sent to CS for the cost of replacing the battery, changing the engine oil, and performing an alignment.

Q: Only cranks and starts sometimes. When it doesn't start, I hear a click coming from relay box. I don't think click is coming from starter

Hi there. It sounds like you narrowed many of the possibilities. It sounds like the starter is failing due to possibly worn contacts or a seizing armature. Definitely check all the fuses/relays and replace as necessary. Have a battery test...

Q: Glow Plug System light comes on sometimes and engine has a lack of power when the light is on.

Hi there. Check the glow plug relay and see if its plugged in. Check the circuits to the glow plugs and see if there is power to them when the key is turned on. The circuit to the glow plugs...

Related articles

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...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.