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Chevrolet Cobalt Real World MPG



  • The car computer actually calculates your average m/p/g of the last hour of driving. When I want to know for sure, I do the same thing as you to get an accurate reading. I fill the tank to the rim, I even rock the car and fill it until I see the gas and it stays there so the neck is also full of gas and on the 2nd fill I do the same thing and then I make my little calculations... miles driven / gal. of gas.
    That's the only accurate way to do it. If you stop the pump when it clicks, that no good.
  • I always calculate my own milage... that's something we were taught how to do when I was in math class way back in elementary school.... the computer always reflects differently (usually lower) than what I get.

    Your skeptical demeanor is a little on the side of I don't like how you're talking to me. If that's not what you meant, that's fine no foul. Don't assume that everyone on here is an idiot.
  • I now have about 4700 miles on the Cobalt and have seen little improvement in mileage. I have been averaging around 24 in mixed highway/city driving. I just returned from a long highway trip, around 400 miles in 98% highway and got 29 mpg (not computer average but miles divided by gallons). Still a little disappointing, but the car rides well, quiet and steady. I am beginning to think that the larger tires (16" w/ machine face aluminum wheels) may have something to do with the mileage. I use a light foot for acceleration, use the cruise control most of the time and watch my braking. I hope that improvement may come in the near future.
  • timb24timb24 Posts: 3
    Update to my previous post - I now have 3300 miles, and have seen improvement. I took your idea powderkegg and switched fuel type, and saw an immediate improvement. It's also warming up around here (North Central PA), so I'm not wasting as much fuel warming up the car. Same mix of driving mostly highway, and I'm getting in the 33-36 MPG range. All around, love the car. I got what I expected.
  • malexbumalexbu Posts: 169
    switched fuel type, and saw an immediate improvement

    Can you clarify this? I've been diligently monitoring MPG in my cars for years but could never correlate the results with the gas brand used. I prefer Shell, then perhaps Mobil/Exxon, then perhaps Sunoco, but this is all very non-scientific.

    Due you have any data demonstrating a certain gas brand's advantage?
  • Here is the information from the post that outlines my "experiment." No scientific data, just trial and error and a little advice from fueling experts.

    I've read in other parts of this forum and other magazines that short shifting and under-accelerating will negatively impact your gas milage. I have an 08 cobalt xfe and have gotten 42 mpg during my trip. That including resetting the DIC when I fueled the vehicle and about 5 miles of non interstate driving before I entered the interstate. I don't get that all the time, but it just shows that it is possible.

    Another interesting bit of information and take it for what it is worth. I always use sunoco gasoline. I am a firefighter at an airport (Harrisburg International, PA) and happened to be having a conversation with the manager of the aircraft fueling station. We were talking about fuel prices and etc and he stated without prompting that Sunoco fuel is the best fuel on the market. They are not affiliated with any brand of fuel. He took me down and showed me samples from thier fuel tanks; some was Sunoco and some was not. The Sunoco fuel looked almost clear, just like real good moonshine! Anyhow, I've been running a little bit of a test. I switch the fuel in my girlfriends car from time to time. She is not as particular with her fuel (she get's whatever is cheaper). I will fill her tank and not tell her where I got the fuel so she doesn't alter her driving. The Sunoco tanks always always always get 3 to 4 miles a gallon better than any other fuel. Try it out and see what happens. It may impact your oil life as well. I've got over 8000 on my current oil change (12200 miles total on the car: 08 Cobalt LS XFE) and the DIC oil life says 27%. Clean fuel, clean oil....... let me know if you get different results.

    Just an update to my milage results. Now that the weather has been warmer I have been getting no less than 36.3 mpg (combined driving) calculated as I fill the tank and not calculated by the car DIC. I drive the posted speed limit and try not to accelerate too heavily so I am not driving like Grandma.
  • timb24timb24 Posts: 3
    I saw my improvement when I switched from an local convenience store which doesn't even advertise their gasoline brand (yea, i know...i went for the cheaper price) to Citgo gasoline.
  • micwebmicweb Posts: 1,617
    Got 34 mpg, '09 Cobalt automatic, SF to LA.

    Usually commute mileage is around 29-30.
  • poncho167poncho167 Posts: 1,178
    Don't have data but it is well known that the quality of a brands gas can be as much as 2-3 mpg/
  • malexbumalexbu Posts: 169
    How would you explain that? If they get gasoline from the same
    refinery, which is quite likely

    I mean no disrespect but I've seen not a single piece of data to
    support the claim that it is well known that the quality of a
    brands gas can be as much as 2-3 mpg

    Different brand differ primarily, as far as I understand, in the
    composition of the fuel detergent added. This may have effect on the
    engine's health, long term, but it's not easy to change the amount of
    energy a gallon of gasoline produces.

    I do prefer to use a brand gas (will use no-name only rarely), but
    this is purely for the detergent.

    Would love to see the data showing the MPG advantage of a brand

    "Well known 2-3 mpg"... People refer to each other's words and an
    urban legend gets born. I could believe 1/2 mpg difference, but 3?..
    Let somebody show the data, not perceptions.

    I watch my MPG like a hawk -- and here is my data: on a trip from TN
    to MA, I filled up at three gas stations: Shell, Sheetz, Citgo. The
    MPG (calculated as "the distance to the volume") for the three legs
    fueled by each was as follows:

    Shell - 36.8, Sheetz - 38.9, Citgo - 36.3.

    (This is for a 2005 Malibu with Ecotec 2.2L.)

    It's either Sheetz is brandier than the rest or... well, something
  • pa356228pa356228 Posts: 34
    My Cobalt LS (4-door sedan) auto gets about 27 mpg average (mostly city driving)
    and gets about 31-34 mpg on hwy. I usually keep my tires at 32 psi as my door panel says 30 psi, is that bad for my tires. How can I get more mpg out of my car? Did change the spark plugs 3 weeks ago, and actually gave my car 1 mpg more when I start the engine.
  • steve333steve333 Posts: 200
    That's pretty much what you should be getting. I avg 25MPG and never get 30MPG highway.
  • laserbluelaserblue Posts: 313
    It looks like you're doing pretty good m/p/g. right now.
    By the way I see it, you should the one giving some advice instead of asking for some. I could add that a clean and well waxed car helps the m/p/g to.
    For your tire pressure, 32 p.s. i. isn't that bad but the ride must be a bit bumpy?
  • pa356228pa356228 Posts: 34
    Yeah, the ride is a little bit bumpy, Should I just go by the door panel psi on tires for safe bet? I know I should be giving some advice. My only advice to give is to keep checking your tires and psi, and also change the oil, pcv valve and all filters every 3,000 miles. Pre-trips inspections is great for your car which can help you in the long run and also saves you costly repairs. Also, drive solo, really does give you more mpg and is easy on your car.
  • laserbluelaserblue Posts: 313
    My tires p.s.i. is always at the vehicle recommendation.
    Like you already know you should check your tire pressure when tires are cold or when you didn't move your car for a couple of hour.
    If you do lots of highway driving your p.s.i. will increase by itself by a couple of ponds, faster in summer or hot pavement.
    If you want my advice let them at 30 p.s.i. an over inflated tire is as bad as a under inflated one. Eventually you will see that your tires will get worned-out prematurally.
  • steve333steve333 Posts: 200
    why on earth would you change the pcv valve every 3000 miles?
    The only filter that needs to be changed is the oil filter. The air filter and cabin air filter get changed at longer intervals.
  • pa356228pa356228 Posts: 34
    I heard that the pcv valve will make a difference by changing it while changing the oil. Heard it from a mechanic once, with some of my old cars I used to have. Doesn't make sense. I know, don't follow through anyways and always when my car needs an oil change, I'll take my car to a chevy dealer to get service.

    Anyways, having you car in line (aliments) will make a big difference on your gas mileage and tires also.
  • eliaselias Posts: 1,898
    32 psi is considered overinflating? Not by me!
    What are the PSI recommendations listed on the doorframe?
    I prefer 34 psi for my vehicles, and 34 is within the range specified on the doorframe for max-speed or max-load operation.
  • steve333steve333 Posts: 200
    Oil Change places always go for the replace PCV valve line, but you notice your dealer will never recommend it. It isn't necessary.
    As for the tires, the door jam says 30, my dealer and Discount Tire always puts them on 35 but I prefer to keep them on 32.
  • laserbluelaserblue Posts: 313
    The tire's p.s.i. is calculated differently from a model of car to another. My 2007 Cobalt door frame says 30 p.s.i.
    I also own a 2005 Equinox this one is 35 p.s.i. and for my show car... a 1977 Chevelle Malibu Classic the door frame p.s.i. requirements are at 24 p.s.i.
    If I take your example of 32 p.s.i. well for my Equinox it would by "under inflated" but for my Chevelle it would be well "overinfalted".
    Don't go by what's written on the tire (like most people do) that's the max-speed and max-load operation of the tire. Always go by the car's door frame recommendations.
    By the didn't mention what type of car you drive.
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