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Chevrolet Cobalt Real World MPG



  • pvs68pvs68 Posts: 2
    I just rented a Pontiac GS (Identical to Cobalt) and according to the in car computer was getting 38 MPG on the highway with spirited driving from NC to ME and back, more than 2500 miles. This was with an automatic transmission too! I was impressed since it zipped along too.
  • Picked up my 09 Cobalt LS/XFE with the five speed a little over a week ago, and have no problem getting 43 to 44 on the freeway. Doing 70 in fifth, with the A/C on.
    This little car amazes me.
  • pa356228pa356228 Posts: 34
    Now, I've being alittle mixture of driving on the Interstate and city. My Cobalt LS is averaging out 31.4 mpg. It was 32.4 but right now my cobalt is about 3,000 miles overdue and will definitely get an Oil Change tomorrow morning (08/21/2009) so, hopefully the mpg will raise back up. Also, my tires are set at 32psi. By the way, my car is automatic, wished I had a 5 speed. Although, I do know how to drive a 10 speed BigRig.
  • I rented a Cobalt in 2007 and played around with various speeds/rpms to see what produced the best MPG (according to the car computer), and found that if I activated the cruise control, while accelerating, right after it switched to the highest gear (4th?), the speed would be maintained at about 38 or 39 mph, and the MPG would register at 58 or 59 mpg. This was when the tires were a little over-inflated (a hot day), and on a very smooth pavement. I watched the mpg drop by 4 or 5 mpg when the road surface changed to very rough (the kind of road that is very loud to drive on). My question is, is the car computer readout of mpg accurate? (if I actually drove a few hundred miles with this setting, and measured the gas comsumption, would the reported mpg have calculated out to be true?) The reason I ask is that I am considering buying a Cobalt, and want to know if the computer mpg is accurate.
  • eliaselias Posts: 2,147
    Car dashboard mpg computers/displays are not very accurate in my experience - often reporting much more mpg than the car is actually getting.
    So no, had you measured distance/gallons, you would have come up with a substantially lower number. Maybe 39 mpg at most, I'd guess.
    But any given mpg-meter tends to be accurate for measuring *relative* mpg differences within that one vehicle.
    So when you saw indicated mpg drop from 58 mpg to 54 mpg, you can be pretty sure that the instantaneous fuel consumption had indeed dropped by ((4/58)*100) %.
    Once you establish the "overestimate" that the dashboard-mpg-meter provides, you can subtract a fixed percentage from whatever it tells you.
    For example, my VW TDI mpg dashboard-computer reads consistently about 10% above the actual mpg, typically reporting 50 mpg over an entire tank that actually yielded 45 mpg.
  • In my 2008 the car keeps very good track of the gas mileage. Keep in mind that the MPG displayed in the DIC is only representative for the last hour of driving. So you may have done 200 miles of highway at 35 mpg and 100 city, heavy stop and go and the car may display 28 or less. But when you fill the tank you will most likely see that you actually got 31 or 32 mpg for the whole tank. For a 300 mile trip from Central PA to Western NY I generally get 34 to 35 mpg. That's a lot of mountains as I venture north at 65 or 70 mph. I keep my tires at 30 psi cold as the car recommends. I have 19000 miles on my car and keep track of every drop of gasoline that the car consumes. My average since I bought the car is 33 mpg.
  • When I first brought (or still leasing yet.) it was calculating 27 mpg at the first 105 miles on the car. When I used to live in PA, my cobalt was getting about 31. Temporary living in VA, as my car was getting 34 mpg. Then, recently about a month ago, my car was still getting 34 consistent. Until, last Wednesday, My cobalt LS dropped to 29.3. Can't fiqure out why.

    Guess, no mpg is accurate on cobalts sensor systems. My manager from work, told me and old fashion trick to know for sure exactly what your car mpg aveage. He told me, just to first, fill up your tank, reset your trip A and Trip B miles. Then, keep track of all your miles, and when it's time to fill up. Check your miles and divide that from how many gallons your car holds. He said, that will be your most accurate. Of course, it all depends on how fast you drive, tires psi set at, and other misc... I haven't tried it yet but, this coming week on Tuesday thru Sunday, I will. Next week, I'm driving back up to PA on a 443.5 miles trip (about 8 hrs.)

    Is there any other tricks to use?
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 21,504
    > My cobalt LS dropped to 29.3. Can't fiqure out why.

    The changeover to winter fuels may have dropped the BTUs in the fuel. Lower mileage than the summer blends.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • eliaselias Posts: 2,147
    it's not really a "trick" to determine mpg by dividing miles by gallons, but since you asked, how's this:
    you could use a super-precision scale to weigh the car, drive a certain distance, then
    measure its exact weight again.
    no stopping for burgers or a caf-pow or shopping or hitchikers or rest-areas.
    the change in weight divided by 9 lbs would be the # of gallons used. then divide
    that into the distance in miles and you have mpg.
  • When I arrived here in Pittsburgh from Virginia Beach, My Cobalt LS mpg reach back to normal 35.4. Two days ago, it fell to 32.5. Did notice the difference BTU's. Guess, they figure no one will want to drive in the winter, besides to get what is necessary. So, no one will care about the mpg. Crazy world we live in.

    I'll keep updating now and then, so be patience. Sure feels great to be back home officially. See ya later...
  • cobaltken1cobaltken1 Windham Ohio Posts: 11
    I have a 2009 Cobalt SS Turbo and with checking the mpg,I do it Manuel and by the computer,on the highway im getting between 30 and 34 mpg as long as I keep my foot out of it,if you know what Im talking about. This is my second Cobalt,the last one was a 2007 Cobalt SS Supercharged and the mpg was the same on it. I love my Cobalt.
  • Hi All.

    I bought a used Cobalt 07 with 23000 miles last Friday. I got the oil changed on Monday, and the air filter replaced as well.
    It is giving me 24 mpg in the city of Houston, which involves many miles of slow traffic and also a few miles of freeway.,

    I don;t understand what I would have to do to get the mileage to a similiar value as you guys are getting, close to 30.

    Any ideas?
  • It is a 2.2 liter standard transmission coupe .

    24 mpg is the computer readout.

    I hope you have some good suggestions.
  • steve333steve333 Posts: 201
    My '06 averages 24 MPG mixed city and freeway. I have no idea why those guys get such great MPG.
  • It really depends. I have a 2008 Cobalt LT sedan with an automatic and I average in the high 20's. My commute is 50 miles each way with a mix of moderate to heavy traffic. I live in the suburbs of New York City and I work in the city (Queens). Because of the crazy unpredictable traffic I've gotten anywhere from 25 to 34 MPG.

    If you only drive short trips that have a lot of stop and go traffic, then 24 MPG is probably pretty good. The only way to really improve is to be light on the gas and better predict the traffic ahead of you so you don't have to use the brakes too much. Accelerating from 0 or very low speeds is what really kills the fuel economy. Try to keep a constant speed. I find that I get the best MPG between 50 to 60 MPH. 65 is not too bad, but not optimal.

    My auto equipped 08 is rated 22 City and 32 Hwy so I'm getting exactly what's advertised.
  • imidazol97imidazol97 Crossroads of America I70 & I75 Posts: 21,504
    >what I would have to do to get the mileage

    In jest here, move farther away so you have more freeway type traffic. On that free way gently drive 55-60. Faster speeds mean more air resistance and turbulance around the shape of the car. Also when traffic slows keep your speed up above what must be 40 or a little over so the transmission is in 4th gear (the tach drops another notch); it seems in 3rd at slower speeds the economy just isn't there.

    This is based on my experience driving around the area in the Cobalt 2.2 with automatic we bought for our son. At 55 or below on a level road the average hits 40. Add an occasional stop or turn and the average is 35-36. Once the car is warmed up just reset the mileage gauge and see what you're getting in various parts of your drive. The stop and go is probably 20 unless you're gently accelerating and trying not to have to stop.

    Another factor might be the gasoline if it has a higher percentage of alcohol.

    2015 Cruze 2LT, 2014 Malibu 2LT, 2008 Cobalt 2LT

  • My research tells me that the cobalt probably will not survive much longer as GM is bringing the Cruze to the states. It is built on one of GM's Opel platforms and promises to be a much better car than the Cobalt. The Cobalt (besides SS Turbo) is a terrible attempt at a small car. The interior quality is horrible, it practically rolls over on itself in bends, and the electric assisted power steering has no feedback or feel. The 2.2 is noisy, down on power, and utilizes the oldest technology. The 2.4 is a much better engine. The 2.0L turbo in the SS has direct injection, twin cam, and variable valve timing on intake and exhaust. And it produces 260 hp, enough to power the cobalt to 60mph in 5.5 sec. The Cruze will use the 1.8L that was in the Saturn Astra which is a complete dog (128 ft lbs torque). However, they will offer a 1.4L turbo with around 140-150 horse that supposedly achieves 40 mpg highway (EPA estimates) in the Cruze. Hopefully this next small car from European GM will handle like a small car should.
  • I don't really understand where you are coming from. I have a 2008 Cobalt LS XFE and the car does exactly what I bought it for. In my first year of ownership I drove the car just over 15,000 miles and spent only $780 in fuel and less than $40 in maintenance (for one oil change). I did need to change the oil twice but one change was free at the dealer. The car is stylish, rides nicely and has decent features for what it was bought for; to be an economical mode of transportation. If you want a real sports car than don't buy a Cobalt... not even the SS model. Get real.
  • I bought my 2007 2LT red coupe in Oct., 2007 with 3 miles on it, and I broke it in for 1,200 miles instead of 500, by varying RPMs up and down, up and down repeatedly. I change oil & filter every 3000 miles. I now have 15,300 miles and ALWAYS get 38 - 42 MPG, and sometimes 44 and 46, with Valero regular. I've been wondering about the accuarcy of the onboard MPG computer.
    I'm in Northern California with temperature 50 - 70 all year.
    For a sporty car, it rides very well and is quiet, with underhood sound insulation and 1" thick foam engine cover. I can't even hear the engine. Tires are Yokohama AVID TRZ, kept at 33 PSI.
    I'll try to find out the accuracy on the onboard MPG computer and send you any info. I get, if you send me your email address.
    My 2LT is the high-end, with seat height and lumbar adjustments, and Daytime Running Lights. The electric steering is superbly tight, with good weighting. This car has been marvelously designed and assembled. The door hold-open even has 3 positions,
    instead of two.
    I'm 73 and have been a car enthusiast all my life and have been studying the Consumer Reports for 30 years. They are usually accurate with reliability and comments, but their comments about the Cobalt are for a different car, not the 2LT!
    I customized this car with red seat covers and painted a lot of the inside red, and painted wheel covers black. I painted the keyholes red too. I don't know how to include images in this reply. If you'd like to correspond more and see photos, send me a reply and I'll try to send them to you."> God bless America and vehicles with American marques and MADE IN USA (Lordstown, OH). Ted
  • Please see my reply #296, for very good news about my 2007 Cobalt.
  • Please see my reply #296. I always get 38 - 42 MPG highway and sometimes 44 or 46. This is highway with no traffic jams, no slow traffic, no steep hills.
  • Please see my post #296, with automatic 38 - 42 MPG and sometimes 44.
  • has a huge selection. It's best to call them and speak with the rep. If you replace the filament bulbs with LEDs, you will have to
    order a load-resistor for each one because the LEDs draw much less current than the filament bulbs. If you don't use the load-resistors, they will flash very fast, called hyper-flashing. BUT, the load-resistor has to be wired across the LED, and it generates heat, so you have to mount it on a flat surface with two screws. One of the ones I got broke at the wire-to-resistor solder joint because there was not strain relief. I returned them because I did not have a flat spot to mount the heat-generating resistors.
  • Please see my Reply #296. No service station will put hydrogen into a tire because it will explode. They do put in nitrogen for a fee of $5 to $12 per tire. The benefit is that the tire pressure will vary less with changing temperatures beause pure nitrogen expands and contracts less than air, which is 80% nitrogen and 20% oxygen.
  • That's a good point about a clean and waxed car. I keep my with a car cover and wax it 3x per year with Turtle Wax Blue Ice and I get 38 - 42 MPG always highway. Please see my post #296.
  • eliaselias Posts: 2,147
    just so you know.. there is no benefit to extra nitrogen in a cobalt tire or any passenger care tire, except for lining the wallet of whoever sells it. the idea of hydrogen in the tire is horrifying and reminds me of the JATO story legend ...

    btw, measure distance-driven/gallons to see the real mpg and compare with dashboard mpg-meter... i bet you'll find the dashboard usually off by the same percentage and reading a tad high in your case.

    I always liked cobalt styling! almost bought one but waited for cruze. :}
  • eliaselias Posts: 2,147
    i avoid waxing cars...
    let's just say/suppose it's for mpg reasons: i figure the weight of the wax costs more mpg than the smoothness/airflow at such low speed.
    but seriously folks, the clearcoat under the wax is just as smooth as a layer of wax on top of it, isn't it ?

    for aircraft the weight of the paint really matters - iirc, some aeronautical painter discovered a way to use thinner layers of paint... added up to hundreds of pounds per aircraft... less weight, saves the airlines BIG $ on fuel.

    happy travels...
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