2007 Impala poor fuel mileage

[ezmobee]

We just bought a pre-owned 2007 Chevy Impala with 35k miles on it. It has the 3.5 V6. We are very disappointed with the fuel economy we've been getting especially since that was one of our primary reasons for buying the car. We traded an AWD Pacifica in on it. We're only getting around 21-22MPG average on a tank of gas with mixed driving, mostly highway. The car runs and drives fine but it does do something that may be a clue to a problem: it seems to shift from 1st to 2nd ridiculously early. The car is barely rolling when it's already shifting. It does this smoothly so it's not overly annoying but I wonder if it's normal. Anyone have any ideas why we're getting such poor mileage? My worn out 2000 Buick Regal with a 3800 was averaging around 24 for the same trips!

 

[Limited-Time]

Re: 2007 Impala poor fuel mileage

Sounds about right. Look here for the advertised specs, which are always high.

 

[ezmobee]

Re: 2007 Impala poor fuel mileage

I did a little research after posting this and it looks like you're right LT. Bummer. Maybe I'll have to start hypermiling.

 

[MikDee]

Re: 2007 Impala poor fuel mileage

You should check to see if any hidden codes come up, Autozone, and some other auto supplies, usually do this for free. It might be a bad O2 sensor, one of them works along with the computer for fuel metering, and if it's bad, the vehicle will be sluggish with poor milage.

I've been through this with my previous 96' GMC pickup

 

[ezmobee]

Re: 2007 Impala poor fuel mileage

Wouldn't that kick on the check engine light?

 

[MikDee]

Re: 2007 Impala poor fuel mileage

Wouldn't that kick on the check engine light?

Yes, usually,,, but sometimes it goes out, by itself, or with help, but the trouble code is still stored!

 

[TilliamWe]

Re: 2007 Impala poor fuel mileage

Sounds about right. Look here for the advertised specs, which are always high.

Well, the EPA ratings on my 2004 Impala (3.4l V6) are 21 city and 32 highway and are a bit low, actually. I consistantly get 33mpg on the highway.
I see that the 3.5 in an 07 is rated lower at 20/29. I would still think it should do better than 21mpg on mostly highway driving, though. What speeds are you driving at on the highway? Is it very hilly? Are you sure you have it in overdrive?
As far as it quick shifting, well, it's trying to "improve" the economy. Maybe GM played with the gearing, cause my 04 with the 3.4 doesn't shift early like that. As a matter if fact, it's geared so tall that full throttle 1-2 shift happens at 47 mph. Yes 47mph. Needless to say my engine is loping along at 70mph in overdrive!

 

[ne7800]

Re: 2007 Impala poor fuel mileage

All-in-all, the 2007 Impala produces respectable gas mileage for a large sedan. When equipped with either the 3.5 or 3.9 liter six-cylinder engine, the roomy Impala delivers gas mileage between 28 and 29 miles per gallon on the highway. Results with the available 5.3 liter V-8 aren?t anything to sneeze at either, with a rating of 16 city / 24 highway. The Impala is a big, comfortable ride that?s conservatively priced and well suited to soaking up the highway miles.

i pulled this off a web site with a review of the impala

 

[ezmobee]

Re: 2007 Impala poor fuel mileage

York to Harrisburg on 83 everyday is kinda like high-speed city driving and it is very hilly. I have no doubt that with the cruise control on I-80 heading west I could get great mileage however I still think I should be doing a little better than I am on our normal commute. I don't see how my old tech 3800 powered Regal got better mileage. By the way, the quick shifting thing only happens if you loaf it. If you get on it it seems to run the gears out normally.

 

[roscoe]

Re: 2007 Impala poor fuel mileage

Heck, I get 17 with the Trailblazer - towing the boat.

 

[TilliamWe]

Re: 2007 Impala poor fuel mileage

ez, I just talked to a former co-worker who has a 3.5 Impala. He doesn't keep close track of his mileage, except when he has to use the car to sit and power a computer after running on the highway for a while. He says he's getting about 26 on days like that. And that's on flat ground here in Illinois. He also has had a couple of company cars with the 3.4 and he says the newer 3.5 is definately not as fuel efficient.
Umm, the hills in your area are commonly referred to as Mountains! When I took my 3.4 power Impala from Youngstown, OH area to Annapolis, MD, it "only" average about 28mpg. So I lost about 3-4 mpg due to the mountains.

 

[ezmobee]

Re: 2007 Impala poor fuel mileage

I knew the 3.5 wouldn't be as fuel efficient as the 3.4 but having driven one with the 3.4 I'll gladly pay the price. Those were dogs! I love the car though so I guess I'll just keep feeding it.

 

[gonefishie]

Re: 2007 Impala poor fuel mileage

try a K&N air filter, it should do you some good.

 

[tommays]

Re: 2007 Impala poor fuel mileage

I did the K&N on are equniox and it did NOTHING

 

[MikDee]

Re: 2007 Impala poor fuel mileage

try a K&N air filter, it should do you some good.

Yes, This plus Mobil one synthetic oil, it works the best of all the over the counter synthetic selections (I haven't tried Royal Purple, or Redline yet?) Your engine will run smoother, stronger, cooler, over conventional oil. I noticed the extra power, as soon as I stepped on the gas the first time, Also the lower friction seemed to make the car coast better, IMO

 

[MikDee]

Re: 2007 Impala poor fuel mileage

I did the K&N on are equniox and it did NOTHING

Thats because you had your foot in it more!

 

[ezmobee]

Re: 2007 Impala poor fuel mileage

Also the lower friction seemed to make the car coast better, IMO

Dear god, if this car coasted any better it wouldn't need a motor!!

 

[gonefishie]

Re: 2007 Impala poor fuel mileage

Maybe I'll have to start hypermiling.

The cost of all the starters you have to replace will far exceed what you save in gas if you start doing that. Not to mention the road rages you would get. Lot of peoples have poor depth perception and can't tell how far your rear bumper is from them. They won't hit the brake unless they see your brake lights. Hypermilling is just plain impractical.

 

[TilliamWe]

Re: 2007 Impala poor fuel mileage

I knew the 3.5 wouldn't be as fuel efficient as the 3.4 but having driven one with the 3.4 I'll gladly pay the price. Those were dogs! I love the car though so I guess I'll just keep feeding it.

If you drove an Impala with a 3.4 and thought it was a dog, you are either 500+lbs, you only drive up the Kittaning Mountains with the rear park brake on, or the car was sick. After having put about 350,000 total miles on a Century (3.1) and 5 Impalas (3.4s) the last thing I would describe them as is "dogs". Yeah, the gearing is a little tall for my liking (very strange to still be in 2nd gear at 75mph in an automatic!), but the motors have plenty of power, and I have never needed more. And .1 liter bigger, in the exact same engine family can't make much difference!

 

[642mx]

Re: 2007 Impala poor fuel mileage

We just bought a pre-owned 2007 Chevy Impala with 35k miles on it. It has the 3.5 V6. We are very disappointed with the fuel economy we've been getting especially since that was one of our primary reasons for buying the car. We traded an AWD Pacifica in on it. We're only getting around 21-22MPG average on a tank of gas with mixed driving, mostly highway. The car runs and drives fine but it does do something that may be a clue to a problem: it seems to shift from 1st to 2nd ridiculously early. The car is barely rolling when it's already shifting. It does this smoothly so it's not overly annoying but I wonder if it's normal. Anyone have any ideas why we're getting such poor mileage? My worn out 2000 Buick Regal with a 3800 was averaging around 24 for the same trips!

Have you checked the air filter? With 35K miles on such a new car, it's probably been over-looked. A restricted filter will kill gas mileage.