I just took delivery of my 2011 on Saturday. The dealership filled up the tank to about 3/4 and I reset all of the trips and MPG settings. So far I've put about 120 miles on my HHR and I'm averaging around 25 mpg. Most of this is driving around town. I have about 8 miles a day that I drive on the highway. If I can average in the mid-20's I'll be saving a ton of money every month compared to my gas guzzling 1995 Explorer.

 

Congratulations!
It should get better as it breaks in.
I used the instant MPG setting for a couple of weeks to see how the skinny pedal affected the MPG.
Then switched it to AVG MPG except to check stuff.
The first few thousand miles I'd AVG about 28 MPG using full tankfulls to AVG with.
Since it's been broken in it gets about 31-32 in the summer & 28 in the winter unless I get boost happy
Best tank full was 33.5 MPG over ~525 miles IIRC

Mine's the turbo 2 liter but yours should also get better MPG as it breaks in. Enjoy.

 

Thank you much! It's actually somewhat broke in...it was a fleet vehicle so it has like 13,500 miles on it. I picked it up for a really good price compared to what others are asking for here in the Atlanta area.

 

On your next oil change use synthetic oil. It helps, since most fleets use dyno oil.. My SS with turbo upgrade kit get 34 average fwy.

 

Good to know...I'll make the switch!

 

bringing this old post alive again haha
but i do use synthetic oil in my LS automatic, shifting is nice but Im noticing that I get a kind of "pull" or hard gear change when I hit 60KM/H, kind of feel the whole car jerk but violently but you feel something a little off. But arent you supposed to get better mileage on the highway compared to city driving? As soon as i hit the highway my mileage drops significantly, and Im not booting it, maybe doing about 110-120KM/H. I actually do better in the city..and WOW does mileage drop if I have AC on

 

GM did very extensive tests on this. Test after test, after test, has shown that the average consumer will not notice SIGNIFICANT gas mileage increase on a daily or weekly basis (usually less than .3 MPG) Depending on annual mileage accumulation, YOU MIGHT NOTICE A DIFFERENCE, then.

Use synthetic oils for other reasons.

 

I average 27-29mpg summer (24 mpg winter) and have hit a high of 33mpg on one tank last year. I run full syn oil in all of my cars but did not notice any mpg increase. AC definitely drops your mpgs dramatically I can lose as much as 3-5 mpg per tank if I run the AC vs leaving the windows down. My car is a base 2.2 LS.

30mpg is difficult for me to hit. If I run all highway it can happen, but mix in any city at all and I am back to 28-29 at best. If I lived in a flatter area, I would imagine I could avg over 30 mpgs but if you have hills, you can expect to be just shy most of the time.

 

28-29 mix is great. Remember they were rated at 22 city 30 highway. That's an average. Can be lower or higher. So if you are averaging 28 that really good. I do mostly all city in my 2.2. I average 27 around town. Highway I normally get around 32.

 

Although the AC will reduce mileage (up to 8% and as low as 5% depending on vehicle and system), I doubt if it is to the extent that some owners are suggesting.

I consistently have the AC on (NEVER turning it off over 5000-10000 miles)....especially on vacation trips...and experience as much as 34.8 MPG at 70 MPH on the most recent trip as well as many others over the same route.

ALL AUTOMOTIVE publications, AAA, Motor Trend, Car And Driver, Wards, etc. state that to achieve the highest MPG with a vehicle from the mid 90's and newer, it is best to use the AC with the windows rolled up.

And although highway mileage has been discussed on several hundred threads, I will mention 9 times out of ten, the poor mileage is due to driving skills...unless there is a MAJOR mechanical problem with the car.