i have very pour millage in my 2009 chevy aveo is 45,000 mls.
Are you sure you are measuring it correctly? How is the car running? That is way off of 25 city, so I would suspect you would be noticing some driveabilty issues or it's leaking.
any errors from ECU? maybe o2 sensor?
is there a huge gas smell? tailpipe smells gas? or under the car gas smell? that low mpg would make me check the engine sparkplugs to see how the car is firing. also, check the fuel lines for any leaks. are you keeping the tires properly inflated? there are many factors. start on the basics to see if any improvements can be done. http://www.ehow.com/how_7370030_improve-mpg-chevy- aveo.html
Is this summer driving using the air conditioner? If so the 2009 aveo i owned when using the air conditioner it took 3 mpg away . Also if yours is a 2009 there is a recall on the spark plugs and their wiring. One other note when i had a passenger it would effect my gas milage.
Looking for a Used Aveo in your area?
CarGurus has 1,125 nationwide Aveo listings starting at $995.
Search Chevrolet Aveo Questions
Chevrolet Aveo Experts
Related Models For Sale
Used Cars For Sale