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Discussion Starter · #1 ·
Ok here are the facts. I am averaging around 8 MPG city in my brand spanking new 2008 Acadia. Its only got 427 miles on it and it started at 121. So basically I am on my 3rd $70 tank of gas and I only went 300 miles. Call the dealer and the service guy tells me its "breaking in" it will get better around a few thousand miles. The dealer said no way break in shoud take that long nor should MPG be so poor. I did tests and all kinds of resets on the MPG to get some additional info. Started out from dealer at 12MPG and went all the way down to 5.9 after a few days of all city driving. Reset at that time and did service guy recommended test. Took it on highway and got it all the way up to 21.9 before it started diving again. Reset once again, decided to try all city for few days and see what is true city MPG. Averaged 8.0 MPG with a very very soft foot this time. Called the dealer again and he said reset MPG every morning for week to get a daily figure. I took it on highway tonight with another reset and again, even on cruise control, I could only get 21.9. Now its taking its usual dive again. I don't know if I can afford all these tests. They need to look at this car and make it leaner now. Is anyone having such bad MPG
 

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Here's my data point for comparison. If I reset the DIC mpg value on a highway with minimal hills and keep the speed at about 65 mph I get an mpg reading of 28-30 and it stays rock solid no matter how many miles I drive.
 

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Discussion Starter · #3 ·
I want to get a good 40 minutes or so of pure highway with a reset to see if I can get great numbers, then I may not feel so bad. I will use your point of comparison as a gauge and see if I can hit the same or even better, I am only FWD.

I found another post about poor Gas Mileage and people are complaining about averaging 15 MPG city. Give me that and I will be happy

I have seen no posts with numbers quite this low. Maybe its starting in a high gear and eating up all the gas. It does not seem to drive as smooth as the Outlook or Acadias I test drove.

I hate bad gas mileage because I love this car and am glad I picked it over Outlook or ugh the Mazda CX-9.
 

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My Acadia is also FWD. I should note that I had the A/C compressor on during the MPG test. This likely cost 2-3 MPG.
 

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last week i drove around 350 miles going to arizona and my speed between 75-80 mph my average gas is 20m/g..going back to san diego my speed is between 70-73mph,87 octane and the average is 28m/g.I think you will have a good mileage if your speed is around 70 :blob: :cheers:
 

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avalon said:
last week i drove around 350 miles going to arizona and my speed between 75-80 mph my average gas is 20m/g..going back to san diego my speed is between 70-73mph,87 octane and the average is 28m/g.I think you will have a good mileage if your speed is around 70 :blob: :cheers:
70mph makes my mpg drop like a rock. My "test" over the past four weeks has been to adhere to the posted speed limit everywhere I go and this has improved my mpg dramatically (like from barely 16mpg to 21mpg) which I consider a pretty good increase. That's a mix of city and highway driving, though mostly tollway and sometimes stop and go tollway traffic.

8mpg seems absurd. Even brand spankin' new, mine never got mileage that awful. I think I have around 25K on mine now. I hope you see some improvement soon!
 

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I wonder if the parking brake or a brake caliper is sticking because even with a leadfoot behind the wheel we still get 16.
When I drive we'll get at least 3 more MPG.
 

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8 mpg is not normal. 11 - 13 can be expected if you driving habits are really bad, but 8 mpg is just not OK.
 

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are you doing manual calculations, too? I'm wondering if your DIC is off a little (understandably you are getting far too low, but MAYBE it's 10 instead of 8)...

I would run several drive tests, resetting the DIC each time. compare city to highway, drive speed limit, drive less than limit, drive over. keep track of each test. plot a route that will meet the needs of the test (no stoplights, lots of lights, etc).

it may be just a "break in" issue, but I've never heard of something so low.

what fuel are you using? E85? E10? Regular? That will make a difference, too. I get about 4 mpg better on regular than I do on ethanol.
 

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what fuel are you using? E85? E10? Regular? That will make a difference, too. I get about 4 mpg better on regular than I do on ethanol.

Since when can you run E85 in these? Sounds like your running E85 but I am sure that these vehicles are not supposed to run on E85. 10% is almost standard, so I am sure thats okay, that car should not be running on E85 if it is.
I have no clue what we are getting because every time my wife fills up before I can get to it, she puts half a tank in :eek:hno:. If she wasn't so cute, I would be mad.
 

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My SLE FWD have about 17.5 -18 MPG with little aggressive driving in morning hours. All driving in heavy traffic. When I got this car I have about 15 MPG, then after 3000 miles got better.
 

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I feel the pain....I drive 10 miles a day to and from work, stop and go. I do NOT have a lead foot. I baby the Acadia to get the best mileage I can...oh and guess what that is.....13mpg. I've got 2400 miles on it now. BUT with that complaint, I knew what I was getting into when I bought it. I was just hoping it was better than 13 mpg. Total bummer....8mpg does not make sense at all, I would seriously have them check into it!
 

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8 MPG? That is either a bad joke, or you need to drop your vehicle off at the dealer and tell them to give you a new Yukon Denali to drive until they fix your Acadia.
 

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Gas "average" is 16/22.

Expect to be lower than "average" 50% of the time...

I would be suspect of those always tauting above average MPG. If all the hype you hear on this site is true, GMC is the worst marketing car company I know - and is intentionally providing lower than average MPG on their Acadia line...not likely - nor are claims of 30 MPG...

In this fuel market, I can't imagine any car dealer not maxing their "averages" as best they can. 16/22 is the MAX average for the Acadia. Expect to "average" that long term.

I've never received 8MPG though....and definitely not 30MPG. I'm fat on average.

One thing I can guarantee is the $70 fill-ups!!
 

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Cheers to that sign maker!
 

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This is from about.com. You can follow the link or read the pasted text in case the link doesn't work or is removed later. http://cars.about.com/od/fueleconomyinfo/a/epa_mpg_testing.htm

How the EPA tests fuel economy
By Aaron Gold, About.com

Filed In:Fuel Economy


MPG Mileage
The Environmental Protection Agency (EPA) has mandatory fuel-economy tests that must be carried out on all cars (but not all light trucks) sold in the US. Most of the tests are carried out by the automotive manufacturers. The EPA tests 10 to 15% of the cars to verify the results.

Old method (2007 and earlier)
The fuel economy tests are run on a dynamometer, a pair of rollers that works like a treadmill for cars. The rollers can create resistance to simulate factors such as wind drag. The test consists of a city cycle and a highway cycle. All tests are climate-controlled to simulate a 75 degree day and no accessories (such as air conditioning) are used. Two tests, the city cycle test and highway cycle tests, are carried out as follows:

City cycle
Trip length: 11 miles
Test time: 31 minutes
Number of stops: 23
Time spent idling: approx. 18%
Maximum speed: 56 MPH
Average speed: 20 MPH
Engine temp at startup: Cold (75 degrees outside air temperature)

Highway cycle
Trip length: 10 miles
Test time: 12.5 minutes
Number of stops: None
Time spent idling: None
Maximum speed: 60 MPH
Average speed: 48 MPH
Engine temp at startup: Warm


New method (2008 and later)
It's common knowledge that EPA fuel economy estimates do not reflect real world mileage, and are particularly advantageous for hybrids. Because of these known discrepancies, the EPA decided to revise its testing methods. Tests will continue to use a dynamometer. Changes will include:
Higher speeds - up to 80 MPH on the highway cycle
Colder temperatures - tests will now start at 20 degrees Fahrenheit rather than 75
More rapid acceleration
Use of accessories - the air conditioner will be operated 13% of the time
Results of the new method
The new testing methods will drop city fuel economy estimates by 10% to 20%, with hybrids taking the highest percentage. Highway estimates will drop by around 5% to 15%.
The new methods -- which will be accompanied by a new fuel-economy label on the car's price sticker -- will apply to 2008 model year cars manufactured after September 1, 2007. Through June, automakers will be allowed to attach an additional label showing what fuel economy estimates would be using the old test methods.

Current regulations only include vehicles with a GVWR (Gross Vehicle Weight Rating - the maximum permissible weight of the vehicle, fuel, and payload, including passengers) of up to 8,500 lbs, which excludes many large SUVs, vans and pickups. By 2011, manufacturers will be required to apply EPA fuel-economy ratings to medium-duty vehicles with GVWRs of 8,500 to 11,000 lbs.


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That's interesting! Thanks :thumb:
 

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Discussion Starter · #19 ·
Well still no improvement. Average is 7.2 MPG all city. Check engine light has now come on and remote start stopped working, I am taking it in tomorrow morning. They said remote start disables if check engine light is on.

I hope they make it right, I love this car, but early problems like this scare me, especially since this car came off the plant floor Feb 2008.
 

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Discussion Starter · #20 ·
I dropped it off today and the loaner they gave me is a sweet 2008 Chevy Tahoe. What gets me is that this v-8 beast is getting 15.9 MPG. I went with a v-6 car thinking I would save money on gas. Boy this really stinks.

They said this morning that I should get the Acadia back by tonight but I doubt it. I am curious to see what modifications they make, that will make the car run leaner. The MPG problem concerns me more the the recent check engine light.

I will keep you posted
 
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