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GMC Acadia Real World MPG



  • hdaohdao Posts: 20
    edited May 2012
    For measure MPG more accurate, I filled up my gas tank then reset the trip odometer to zero. On my next gas fill-up, I wrote down how many miles I drove and how many gallons that I have just filled-up. Do the math with my cellphone calculator, take total miles divided by total gallons. This should be a right MPG rating. I did it with a long trip from Dallas to Houston with driving 70-75 mph. It was 22 mpg. On the way back, I drove a little slower from 65-70 mph, it was 25 mpg. For a better mpg, ones should maintain speed at 65 mph. When I compared with the information center dashboard of my Acadia, it shown 1 mpg less difference. Note that this is my highway calculation. I have yet measured in city. But I guess it is about 16 mpg since my average combination hw/city is 18-19 mpg. Other factor, I keep changing my oil at 4000 miles or 4 months whichever comes first. Clean the throttle body chamber every year. I use KN air filter and clean it every 6 months.
  • astoppastopp Posts: 1
    My 2008 Acadia SLE AWD with 30,000 miles only gets 4.9 mpg. What could cause this?
  • gmcustsvcsarahgmcustsvcsarah Posts: 1,964
    Have you checked the following on your vehicle already:
    *Are your tires fully inflated?
    *Is your air filter dirty?
    *Is the oil of the proper viscosity?
    *Are the spark plugs running efficiently?

    These would be good places to look (you may already have done so); also has great resources on how to improve fuel economy.

    If this is something you were thinking about having checked out, please let us know if you decide to work with one of our dealerships as we're available to help through the process. We can be reached at (please include the last 8 digits of your VIN).

    GM Customer Service
  • I also brought my 2010 Acadia with 24,000 miles into the dealership today for a gas mileage issue. I am getting on average 5 miles to the gallon.

    In January of 2011, the dealership did a transmission adjustment on my car that lowered my gas mileage by about 2 MPGs. While unhappy with this, my husband and I werent given another option. Since then the gas mileage has continued to lower.

    Today, the dealership called and told me that the problem is simply I need to fill my tank up all the way and they dont recall doing any transmission adjustment on my car that would have affected gas mileage. They say they only did an "ECM" adjustment that would havent affected gas mileage. My husband and I were both present for the conversation in 2011, it was a big deal to us & we know the name of who we spoke to.

    I am very unhappy with my Acadia and wouldnt recommend it to anyone. This isnt the only service issue I have had and taking it to the dealership is a hassle. It just isnt right that I will be forced to trade it in and lose money on a vehicle that I had planned to keep long term.
  • gmcustsvcsarahgmcustsvcsarah Posts: 1,964
    If we can look into anything further for you, tamara1802, please don't hesitate to send us an email at that includes the following information: your name/Edmunds username, the last 8 digits of your VIN and current mileage, and the name of your involved dealership. We will set up a case within our department and continue from there.

    GM Customer Service
  • cs350cs350 Posts: 5
    As a tech in a GM shop I can tell you that unless the check engine light comes on there is virtually nothing we can do "fix" poor fuel mileage. If you are experiencing very poor numbers (under 10?) then we can look at the ecm with the scan tool and check for fuel trim values which may lead to vacuum leaks or fuel pressure issues. We can check for excess brake and driveline drag or poor alignment. Honestly, and this is just my humble opinion, GM mixed a peaky v6 with virtually no torque to an often confused and irrational 6 speed trans and then stuffed them into an overweight SUV. I think the only way to save the Acadia from itself would be to put in the 3800 with the 4 speed trans. Also, there is an update for the tcm that is supposed to help with the car rolling back on hills or something but it also comes with a warning that fuel mileage may be negatively effected.
  • kaydeejaykaydeejay Posts: 14
    edited August 2012
    An interesting perspective from cs350. A 3800 V6 maxed at 200HP, down almost 90 from the Acadia's 3.6L.
    I have to suggest the performance would suffer dramatically.
    Having said that, I have always held the opinion that the 3800 was one of the best motors GM ever built and they only gave it up because the Automotive Press dumped all over it as being a "Low-Tech" push-rod motor.,.
    In the Lumina APV/Pontiac Trans-sport vans, with the 3800, I regularly achieved 27mpg. Admittedly they were lighter with less frontal area but aren't the new engines and transmissions supposed to be "more efficient".
    Perhaps the 240HP supercharged 3800 from the Buick Park avenue Ultra/Pontiac Grand Prix GTP/Bonneville SSei would have given the Acadia enough power?
  • cs350cs350 Posts: 5
    I do understand that the hp numbers are way down compared to the 3.6 but I think you'll find that the torque numbers are way better in a way more usable rpm range than anything the 3.6 can post. It's great that the 3.6 make all that power but stupid that none of it is available under 3500 rpm. How often do you drive around at 3500 rpm? The torque is what gets the car moving off the line, it's also what allows the vehicle to maintain speed and accel (to a point) without needing a downshift. Try to drive your acadia around without forcing constant downshifts. Each downshift is mpg lost. If you want to see something interesting, compare curb weights of the acadia to something like the mid 2000's grand prix's and then consider the mileage those vehicles were able to post. Seems a bit lopsided. Then again, this is all just my opinion, I'm not an engineer. Side note: I agree that the 3800 is one of if not the best motor gm made. I suspect they dropped it due to emissions considerations but I don't really know.
  • jpfjpf Posts: 496
    Another alternative is the 3900 V6. I have one in a 2007 Uplander. HP is rated at 240. I have got 27 MPG in 50-55 MPH driving and 23 to 24 MPG on the interstate (70-75 MPH). In either case, the 3800 or 3900 would be a more durable and reliable option in the long run (i.e. 150-200k miles of ownership).
  • Interesting theories, but we'll never see any of them tested.
    If you go back far enough to my earlier posts, my issue is that I am not able to get even CLOSE to the official highway rating of 24mpg.
    At 60-65mph, flat roads and no downshifts I have almost made 21mpg, which is the bottom of the "range" of 21 to 29 mpg quoted on the window label. I have no clue how 29mpg could be achieved.
    That is the "best ever" number, typical is 19mpg.
    I drove GM company cars for 20 years and NEVER failed to meet or exceed the official ratings (and that was under the older more lenient EPA numbers).
    I bought the Acadia fully expecting to get better mpg than the vehicle it replaced - a 1995 Buick Roadmaster wagon with a 5.7L V8 that consistently delivered 25mpg on the highway.
    THAT is my issue with this car.
  • obyoneobyone Posts: 8,054
    Your mileage with the roadmaster had more to do with the gearing in the 4L60e rather than that pushrod 5.7 v8. That same 5.7 in a '00 Yukon Denali returned 10.5 city and 13 highway.
  • So you are saying a 2.93 axle in a Yukon/Denali will get 25mpg??!!
    I suspect not.
    But you are missing my point.
    My Roadmaster was rated at 26mpg under the old ratings (which would be closer to 23 under the 2008 and later standards)
    I repeatedly got 25.
    My Acadia is rated at 24mpg under the new ratings. I get 19 with a best ever of 21.
    THAT is my issue!
  • sam1940sam1940 Posts: 3
    edited October 2012
    I have a 2011 Acadia FWD and became aware the same rpm vs. speed issue as you. At around 40 mph (city driving speed) the engine rpm is 2000. This is very fuel inefficient. When the cruise is engaged, the rpm drops to 1400 which is the transmission shifting from 4th to 5th gear. Similar shifting changes occur at lower speeds as well when the cruise engaged. Of course, I don't normally drive around town with cruise control engaged. Thinking that it should not be necessary to engage cruise to control to have the transmission shift at town speeds, I wrote GM and they sent me to a dealer to have it checked. The dealer hooked up their computer monitor during a test drive and found as I had experienced, that at 40 mph, the engine speed was 2000 rpm and engaging the cruise it dropped to 1400 rpm. Then disenging the cruise the rpm increased to 2000 rpm. Interestingly, we (dealer service tech and service manager) tested a 2012 Acadis. The 2012 shifted as I would hope, 1400 rpm at 40 mph with or without the cruise engaged. Other words GM had corrected the problem with the new models. CORRECTION OF THIS PROBLEM WOULD BE TO SIMPLY RE PROGRAMING OF THE COMPUTER MODULE LIKE THE 2012. However GM tech support would not do this. So all of us with 2011 Acadias and older are stuck with a gas hog. (GM TAC CASE 71-1048356874)
  • Poor mileage in city driving is partly the fault of the transmission not shifting from 4th to 5th at speeds around 40mph. The engine thus turns at 2000 rpm instead of 1400 rpm if it would shift. Other cars I have driven have an engine speed around 1200 to 1400rpm at 40mph. If you engage the cruise control it will shift up to 5th at these speeds and if you disengage the cruise it will shift back to 4th. I tested a 2012 and this problem has been corrected. The shifting pattern was verified by the dealer. The problem can be corrected by re programing the computer module. I complained to GM and they refused to do anything. This is a matter of poor engineering and a big company ignoring the customer. So long GM.
  • To Caron, GM Customer Service, - the problem will not be taken care of until GM TAC let's the dealers re-program the computer module to let the transmission upshift from 4th to 5th during city driving thus reducing the engine rpms from 2000 to 1400. The driver can force the shift by engaging the cruise control, but in city driving that is silly. Engaging the cruise at 45mph will also permit an upshift from 5th to 6th reducing the engine speed to 1200 rpm. Why can't GM get with it and help out Acadia owners get better gas mileage?
  • kaydeejaykaydeejay Posts: 14
    edited October 2012
    While this may well be an issue, it will not help those of us who cannot regularly get within 4mpg of the heavily published and advertised 24mpg highway mileage for a 2WD.
    My best ever 20.7 was at 60mph across New York State with a tailwind!

    Do we have documented test results to support an increase in mileage at 1400 vs 2000 rpms at the same road speed. That is not a foregone conclusion.

    What changed for 2013? I have a friend driving a GM company 2013 right now and is getting 22mpg with a fully loaded AWD Denali.
  • bdylan4771bdylan4771 Posts: 2
    edited November 2012
    I have owned this vehicle that I originally posted about over a year now, and the fuel economy issue is still very frustrating.
    Customer service representatives remind us that the EPA tests are for shopping comparison purposes only. Those mileage figures were a deciding factor for me in purchasing this vehicle. This is precisely why I am so disappointed with this vehicle. I get pretty close to the sticker figure on other vehicles I drive and no where close on this one. I feel I was misled by overstated MPG figures.
    Please don't give us the canned response to MPG issues. I am not a tech, but we all know the major things that affect fuel economy.. driving habits, tire pressure...etc. Transmission programming? This seems to be an issue, but I am told this all checks out. I assume the MPG testing was done with the same configuration as is available to the public. I know the MPG testing is designed by the EPA but it needs to be performed by them or some other 3rd party. Then, at least we could look at these figures as factual and unbiased and would stand less of a chance of being overstated as I feel is the current situation. I realize this is a bigger issue with the EPA and is beyond GM control.
    I did find these sites interesting. , and Both have admitted to overstating mileage figures and are starting reimbursement programs for those affected, as well as reissuing the MPG figures.
  • steverstever Posts: 52,683
    You forgot the Honda Civic Hybrid. :shades: (US News)
  • monicaotmonicaot Posts: 2
    I posted on here almost two years ago complaining about my Acadia. I just wanted to share that I just got rid of the Acadia and got into a chevy equinox. I feel liberated! Freed from the chains binding me to unaffordable gas and horrific gas mileage! I'm averaging 23 mpg compared to the 12 mpg I was getting in the Acadia, I've cut my car payment in half and am loving the new car! Just wanted to share!
  • huedawghuedawg Posts: 5
    Good for you and same here ! GM ended up buying our Acadia back . We now have a 2013 Traverse and it's doing great ! MPG on the highway is around 24 with awd and 16-17 city . Couldn't be happier ! I would like to applaud GM for the smooth transition and such ! They helped every step of the way . They have renewed our faith , so to speak .
  • kaydeejaykaydeejay Posts: 14
    One more year to go on my 2011 Acadia lease, then the pig will be gone!
    Because no-one at GM or the dealer gives a damn about the real-world mileages of these vehicles, this GM retiree will be looking at NON-GM vehicles for the replacement!
    I can't wait!
    Customer Service - please pass this up the chain in case there is some-one some-where who actually cares about what their customers are saying.
  • kaydeejaykaydeejay Posts: 14
    Wow! On what basis did you get a Buy-Back? Not the mileage I assume?
  • 62vette62vette Posts: 17
    I leased a new Acadia a couple weeks ago. Just been driving it around town then finally on Thursday I had a reason to drive it on the freeway about 140 miles roundtrip. Filled up the night before and then hit the freeway. Mileage started low and kept creeping up, just when I was getting to the turnoff I needed it was at 23.8.Then drove surface streets for a while and drove home, averaged 22.5 for the trip. For a car with about 450 miles on it, I thought this was great.
  • hillenhillen Posts: 1
    has anyone tried a programmer to change shifting patterns
  • huedawghuedawg Posts: 5
    The transmission would not shift . The RPM's were always high . They tried new shift modules and other stuff to no avail . If they didn't buy it back , then by law , it was a lemon anyway and they stood to loose a lot more . That said , they were great to work with and it was a quick process . We had lost all faith in GM but their actions have turned that around . In fact , I was so impressed with the way they handled it that afterwards , I recommended a fleet deal to my employer for 10 Colorado's , which they are currently finalizing .
  • 1gmc1gmc Posts: 1
    Just leased a 2013 SLT1 2WD last week and drove it from Phoenix to Laguna Beach CA. Two adults, three kids, lugage, stroller boogie board etc.., average speed 75+. The trip home included a couple hundred pounds of beach sand and more luggage. Had room for all, locked the cruize on 85 for long streaches and passed a couple 18 wheelers at around 95. Average MPG for the trip was 18.5. Bigest complete, the GPS touch screen froze several times and takes multiple touches to respond.
  • handydadyhandydady Posts: 2
    I bought a 2013 GMC Acadia early this year and feel the same way you do. I am disappointed at GM engineering, the engine has plenty power to have two diving modes, standard for towing and heavy foot folks, and economy for easy driving. The engine stays at high RPM before downshifting for easy driving and will run around 2000 RPM to coast at about 75 MPH. If you want to make up to 26 MPG, keep the RPM between 1400 and 1600; the only problem is that the max speed you will reach is about 55 MPH.
  • hdaohdao Posts: 20
    I agree. My 2007 Acadia can get up to 26 MPG on highway with super unleaded and my average speed is from 65-72. I don't count on display gas mileage meter but calculating by filling up then setting a trip odometer to zero. Drove a long trip on highway from Houston to Dallas. On the next fill-up, I take the total miles then divided total of gallons just filled-up. In city, my Acadia can get around 16-18 GPM. I always try to run over 42 MPH in order to have a transmission shifted to 5th or 6th. Driving under 42 MPH will make it gas sucker as you mentioned.
  • I have a 2013 Acadia and get 17 MPG city driving and 24 on the highway. Have to drive about 1800 RPM.
  • We bought our 2011 Acadia (AWD) thinking it would have better gas mileage than our 2006 Jeep Grand Cherokee. We've been tremendously disappointed and I would not buy another Acadia. The window sticker said 16 mpg city and 23 highway, and we've been no where near that. City runs about 10 mpg and highway is about 16. I've asked the dealer to look at it twice and they told me there's nothing wrong with it. "Must be the way you drive it, your driving mix, etc...". I understand the projected mileage is a range, but to be off by 35% on city 30% on the highway is ridiculous. It's not an apple to apple comparison, but the projected mileage on my 2012 Ford Focus has been dead on.

    Another annoyance is the interior fit and finish. There's a squeak in the headliner of our Acadia that the dealer hasn't been able to find. It's been squeaking since about 5K miles and we have 35K on our Acadia now. Also have had some problems with interior plastic interior trim pieces breaking and falling off. Granted, it's just a squeak and the dealer replaced the trim pieces under warranty. But, I expect a lot more from $40K vehicle...
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