Chevrolet Cobalt Real World MPG

sharkman1

I've had my LS 11 months w/ 21,800 miles and its getting high 30's (30.8 mpg), thats with some spirited driving . Drove to San Antonio last August and the mpg was heading for 34 mpg but topped out in mid 33mpg, got back to Houston traffic

okko1

curious do you have the 2.4

okko1

the internal combustion engine is nothing more than a hotair pump. horse power and torque to weight are options how much hot air are you pumping

cmhj2000

I just shake my head in misbelief.

Only have 150 miles on my 07 2.2 LT 1 W/Auto. Haven't been drving it with economy in mind & won't until I get few more miles on it. More concerned with getting the initial break-in with varying speeds & moderate to hard acceleration for short periods of time etc.

Any who, the computer is telling me I'm averaging nearly 38 MPG. I do have the tires aired up but nothing else. If this car does this on a 1,050 mile trip I have planned in 3 weeks I'll be happier than a pig in slop.

poncho167

Those computers are close but not always perfect. Try the manual way by calculating the gallons and miles at fill-ups to see how close the puter is.

grosloup

The way I do it is by filling the tank up to the rim. I even rock the car to put more in. (the tank neck should be filled to).
Then I put my mileage to "0" and when it's time to fill up I do the same as explained above. Take the mileage divided by the gallons burned, and there you go, you get your exact m.p.g.
The computer gives you the average m.p.g. that you did in the passed hour of driving.
Not to accurate.

cmhj2000

I realize the only way to get an accurate read is to fill the tank a couple times and average it out, which I'll be doing on my planned trip at the end of the month. Have been driving for 40 years.

Was simply commenting I don't believe what the computer is saying.

Will report back my overall average of about 2,500 miles that'll be logged for the first half of Sep.

jaxs1

You are damaging your car by overfilling it trying to get the gas to come up into the filler neck. There is empty air space for a reason.
Just stop it at the first click and average the mpg over 3 fillups.

grosloup

Never thought about that air space.
You're right,there must be a reason for that. From now on stopping at the first click and using your method.
Thanks for the advice.

okko1

i drive nearly the same distance every day it takes about 8 to 9 gallons a week and the average always seems to be with in 1 mile of the mpg of the computer. though this can be differnt depending how hard i drive the car.

cmhj2000

"though this can be differnt depending how hard i drive the car."

I find this interesting. Something for this ole' fart to ponder on.

prdm

Over filling will shunt liquid gas into the vapor canister which is designed to hold, wait for it, vapor. It's possible to destroy the canister this way but I think that would trigger a CEL. If you have been doing this alot get the cannister checked - it's simple.

poncho167

Also, as pointed out on the nightly news, it is bad for the environment for those fumes to escape into the atmospher.

tarco

My Cobalt was averaging 29 mpg when it suddenly dropped to 16-17! Took it to the dealer expecting a fuel leak, but they couldn't find anything. Any ideas on what the problem could be?

grosloup

Is that 29 mpg average coming from a reading of your computer or is it a real mpg test?
Going from 29 mpg down to 16-17 is a pretty big difference.

tarco

Both. The computer reading went down, and now we are in the process of documenting it with fillup receipts, mileage log, and photos of the odometer. Very strange!

poncho167

I have heard of some cars brake pads/shoes sticking causing a drag on the brakes and lowering mileage, but I don't think it was near that much.

grosloup

Did you check if your emergency brake is off, or if you used it recently it could be seized.

okko1

if it is an auto trans. may be an over drive problem. check your rpm should be about 2500 at 65 mph.

tarco

Thank you for all the advice. I will check those out as soon as I pick it up from the dealer. They said that they reset the computer????

cmhj2000

Now at the 1,500 mile mark on my 07 LT 1 W/Auto, have made my trip to Central Wis.

Average mileage since I left the Philly area was 35.6 MPG. FWIW the computer said 36.5.

Will finalize this in a couple weeks.

cmhj2000

Made a 2,700 mile trip, 90% Interstate driving, mostly held the speed limit + 2-4 MPH.

Didn't use the cruise until almost at the 900 mile mark.

Overall average was 36 MPG. Not too bad.

If you want the left lane it handles that with ease too.

Break em' in right and maintain it!!!

Did a first oil change with 5W-30 Pennzoil platinum at 1,500 miles, also installed a magnetic drain plug. Since I'm an Amsoil dealer I'll swing into Amsoil at the oil change.

later gators.

cmhj2000

Forgot to mention that during this 2,700 mile trip the AC was on for less than 500 miles total.

"If" you go by the DIC, the AC will cost you a tad over 1 MPG while cruising at highway speeds.

silverado4x4

Are you using E85 gas? I have never herd of a cobalt getting less than 34 MPG. That kind of drop in mileage and the dealer can't find a problem. Dealers are not alike. Try a different dealer. This problem is serious and needs attention. There will be more problems in future resulting from this kind of fuel consumption. I myself would be all over the dealer until they fixed the trouble!!

steve333

I average 25-26 MPG with automatic. Mix of city and freeway driving.

jaxs1

Lots of people here have posted averaging less than 30 mpg, much less 34.

digitalacid

Keep in mind that all of the automated computer systems in the cobalt are designed to keep running averages. Times of heavy acceleration or heavy traffic will drag your true MPG down. The only way to get a real time rating from the DIC is to reset the Economy computer in motion on the highway. That way it's not taking into account your city and traffic driving. Those are going to be lower anyway. My cobalt gets around 30 MPG in the city and 38-40 MPG highway. In the city I don't spare the gas off of dead stops. I have reset the economy right before I burned out off of a stop and it instantly went down to 7.2 MPG. It depends on which average your looking for really. If you want the whole trip it's not really gonna be an accurate reflection of what the car was really doing.

smogdung

By the way, did you know that there will be a 2008.5 Cobalt SS Turbo with 260 hp?

Over in the Mazdaspeed 3 forum there is a link to the engine tests that have been performed for what I guess is the replacement for the SS SC.

poncho167

I read about the Cobalt turbo as well but it hasn't been officially confirmed as of yet.

smogdung

I tested a 2007 5 spd Pontiac G5 GT today (same car as the Cobalt SS 2.4L 5spd)...1st & 2nd gear scatch (with wife & salesman aboard).....quite nice for the price....

Tested a MazdaSpeed 3 & SS SC yesterday....serious fun! When ya hit 3rd in the MS3 it's like a rocket goes off under your butt! SS SC more linear.

poncho167

Now autob--g says that the rumor is true, the SS Turbo will be built in 2008, same as the HHR Turbo.

dave8697

find anything?
I had a caliper grab my front brake rotor on one side and I went from 26 mpg down to 22 mpg in a V6 weighing 3650 lbs empty. After fixing it with a replacement caliper and a new mass air flow sensor I was back to 28 mpg. That's why 29 mpg for a Cobalt to start with is unhealthy.

my08cobalt

What type of milage is everyone getting for a 2008 Cobalt LS for driving around town and local highway driving combined. I am only getting about 19.5 MPG.

grosloup

It's still new. Give it some time and you'll have a better MPG rating. After driving about 700 -1000 milles with your Cobalt you'll start to see a big difference. Remember depending in which region of the country you are driving, cold weather, wind and snow are factors that decrease your MPG. When G.M. estimates MPG rating on their new cars they test them on a nice paved road with no bumps nor cracks, no wind, no hills, no curves, no traffic. They get the best out of it. We can't do the same in our cities or highways.
Don't despair.

poncho167

Also don't forget the change in gas at this time of year and ones driving habits. I have never gotten below the suggested mpg on any GM model so hang in there. On the rightside of this page in Learn More review section where there are 3 posts listed with two showing their current mileage.

jtk152

Exactly. Cold ambient temps and winter blend gasoline will lower your fuel economy. I do nearly all hywy with my 2007 2.2L, AT. Summer I would average just under 32mpg per tank, now I average just over 30mpg per tank. (Buffalo NY)

Joel

cmhj2000

My 07 LT1 sedan W/Auto just made another trip from the Philly area to central Wis. and back. Temps were "going both ways" around zero starting out to mid 30s upon arrival 16 hours later. I drove like a bat out of hell and averaged 33 MPG actual, 33.9 per the DIC. Most fill ups contained some ethanol.

During my around town driving I usually average 29 MPG.

I keep my tires up around 38 Ftr./ 32 rear and use 5W-30 Amsoil XL.

Car now has 6,500 miles logged. Mileage hasn't changed over 0.5 MPG since it had 200 miles logged.

rlenker

I have a 2007 2.2 auto with 4400 and I can't get better then 14 city.
With some highway mixed in. What shoud I look at?

my08cobalt

Do you mean you are actually driving in the city or are you actually driving locally. Just curious.

poncho167

I would have a real concern if I were getting 14 mpg around town/city. The car should get no lower than low 20 mpg in the city even with the winter gas.

cmhj2000

Driving style, environment and habits along with how the engine was broken in, additives if any used etc., can & do give strange results.

Without being able to witness how the car is driven would be pure speculation from my vantage point as to why you're getting the mileage claimed.

If I were getting 14 MPG city in my Cobalt I'd have it scanned, access my driving habits & or driving style. Some city driving can severely drop mileage with excess idling, excess warm-up time & very short trips etc.

35 years of wrenching and I've yet to this day been surprised at claims, as in most cases they can be proven.

cmhj2000

Should add I've seen odometers that were off enough to give what appeared to be very unusual readings.

One thing I've always done was to run a new car thru a known distance to determine odometer & speedometer accuracy.

atomicshark

I just bought an 08 Cobalt LT1 sedan with an automatic transmission yesterday. I will use it to drive into Queens, NY and back to Long Island. That is about 50 miles each way in a mix of stop and go rush hour traffic.

I was wondering if anyone here has a similar car and commute as me and if you could tell me what your fuel economy is.

Thanks in advance.

bobokadof

i average between 26~27 mpg. 34~35 highway though

robmonster

I have 37,000 miles and I average a little over 27 MPG in mostly city driving. On the highway I have never gotten less than 32 MPG and have gotten as high as 37 MPG. Average highway driving seems to result in around 35 MPG. When I push the car, I get about 26 MPG and when I am easy with it I get about 28 MPG. When my fiance drives my car she gets about 25 MPG (she drives it like a race car).

Moreover, I just got new tires (the original Pirelli P6 tires sucked) so I will post later with mileage numbers for the new tires.

steve333

You're lucky, I never get mlore than 26MPG freeway and I average below 25MPG.
I have the Pirelli P6 also and I agree they suck. What tire did you replace them with?

robmonster

I replaced the Pirelli P6s with BFG Traction T/A tires in a slightly bigger size (P215/55R17 vs. the original P205/50R17). No tire dealers in the area had 4 tires in P205/50R17 and my neighbor is on vacation so I couldn't get the tires and use his garage to mount them. FYI, I have heard great things about the Michelin Pilot Exalto A/S as a replacement for the P6s. Pretty much anything out there will get better grip and make less road noise!

georgecavalier

I get around 28-30 MPG with my 2.2 auto. This is great for me since I don't usually drive with a light foot. My 2001 Z24 got around 24.5 on average so Chevy has improved.

steve333

It pisses me off that I currently get a little over 24MPG. There has to be a reason for it.

just84wvu

My trip on the interstate put my Cobalt from 16 at dealer to over 220 since Saturday when I bought it. The dealer is over 100 miles away for those wondering about the difference already. I filled up yesterday and since most driving was highway I was at 34.2mpg. My biggest concern will come with city driving which is what I do alot of. We have lots of stop and go traffic where I live and I was hoping for something good on city not highway. I hope the Cobalt does well or I'll continue to feel remorse for being pressured into this car by the dealer.