Terrible Mileage- 2007 Cobalt 2.2 Auto

[ARCANGEL]

are you serious!!! I have an 07 cobalt SS/SC and my mpg is 23.5 something has got to be wrong!!!! you should check it out man!!!

[MechEng]

Originally Posted by Minnesota Nice

Lately I've noticed my economy dropping a little bit. It's definitely due to the colder weather. The car must have to work that much harder.

You are correct. Combustion produces heat that expands the air in a cylinder to move the vehicle. The colder it gets the more heat that is lost through the cylinder block walls during combustion. The heat that is lost is no longer used to propell the vehicle. So the colder it gets the more energy that is lost from your engine.

[2005 Equinox LS]

The ones that I got for rentals got around 25-26 in city driving. Must be something up with that. Moms Aveo gets 26-27 in town.

[Minnesota Nice]

For what it is worth (I didn't re-read the thread a few days later so I may overlook something already said), but are you due for an oil change pretty soon? What about your air filter or other periodic maintenance?

I noticed my gas mileage was...abysmal several hundred miles before my first oil change.

[Rocket7]

Your problem could be something as simple as a bad coolant sensor, or sensor going bad, which would cause the computer to deliver more fuel than needed. GM 4 cylinders cars that I have had in the past have consistently gotten between 36 and 44 miles per gallon, depending on tranny. I would have it checked.

[epaulo]

calculate the mileage urself. i've found the guage to be wrong by several mpg, i have an 06 ss supercharged, and i get around 25 city, and mid 30's on the high way. combined i get 28-29 mpg. theres people with tunes that get combined mid low 30's. and near 40's on highway.

[PAULSTS1]

There are two areas to consider, they both involve pounds: First there's tire pressure, when constantly doing highway duty you should increase the pressure about 4 lbs more, to decrease rolling resistance.

The Second is a little more delicate: How much poundage is the little 2.2 having to propel around? If small engine has to launch say 300 lbs, it takes a lot more horsepower a far longer time (means more fuel), than it would take to launch a meer 105 lbs. This may explain why a V6 powered vehicle could conceptually get better overall mileage than a 4 cylinder one, it is designed for heavier duty. This is the main reason, I've talked some of my more "Corn Fed" acquaintances out of buying some smaller lower powered cars, and recommended more powerful, and stronger suspended vehicles.

This is just meant to give possible answers to the question of "Terrible Mileage", and not intended to provide license for improper liberty to be taken.



4.6 Northstar powered!

[CHASLS2]

Originally Posted by Will123w

We bought a cobalt for the wife last year when her 10 year old Saturn finally kicked the bucket and for the most part I like the car. It's comfy, theres a decent amount of legroom in the back and it's relatively quiet.

The big problem though is gas mileage. Purely on the highway the car can only average 30 if its either perfectly straight or downhill, otherwise it hovers in the 28 mpg range.

The city mileage is atrocious, right around 15 or so. The avg. mileage according to the computer over the last couple thousand miles is 20.3 mpg.

Now we didn't get a bigger car because of mileage and I'm very unimpressed with it so far. It doesnt fall close enough to the 22/31 ratings for me to be happy, and I'm tired of getting around 200 miles to a fill up.

My question, is it possible for the dealership to reflash the computer, er perhaps something mechanically is wrong. I know though that when I take it in they will just say, oh well mileage varies. Sure it does but I got better mileage in my 95 lumina with a busted 3.1

My 06 a6 C6 Vette gets 28 highway and around 16 city and i drive it kinda hard.

[Will123w]

Thread ressurection! hehe

Well if ayone is still interested I finally got around to taking the car into the shop about 2 months ago to see what was going on. Turns out the car was running really rich, but would lean out over time so with all the short trips we make the mileage suffered twice as much.

The shop ended up taking care of the computer issue and we had an alignment and rotation down and I'm happy to report that average mileage is up to 25 with a 75/25 city/hwy split. I'm definately much happier now that we get almost 100 more miles out of a tank of gas.

[RoGuE]

I wonder if my Ecotec (in my Malibu) has a problem too. It has been getting worse and worse each time I fill up. My last tank got 19 mpg...horrible considering at one time I was getting 25 mpg in similar conditions (all city).