After my first full tank, 21.5 mpg. 99% city streets.

I was hoping for better, but considering I stop at drive-thru windows almost every day and it's all short distance stop and go below 40 mph with A/C, it's not bad I guess.

 

First tank for us was 24.4 . Same thing, some drive thru some sub 40 mph, a bit of highway driving thrown in the mix. Car is a 2.2 with a 5 speed, 2006 model LS.

 

I drive 40 miles/day round trip to work, and its about 85% highway 15% city, though the trip home can be stop-n-go due to traffic congestion on the interstate.

I get around 28mpg for a week if I do minimal driving on the weekends around home. If I get stingy with the gas pedal, go to Neutral at stoplights and downhills I can get it up to 30mpg. Those are actuals, not DIC averages. I've found the DIC is usually .7-1.0 mpg higher.

The only "mod" is Mobil 1 oil.

2007 1LT, 14,000 miles.

 

My first tank was 27.6 by my calculations but the DIC only reported 26 (I guess it idled alot at the dealership. On my second tank I reset the average MPG on the DIC...it's reading 28.5 right now, with mixed driving, but mostly rural state highways at about 57 mph. We'll see how it compares to the manual mileage calculation after this tank.

 

32.4 on the 400 mile return trip from Ohio where I bought it. Cruise control @ 70-75.

 

Just took our first long trip, 75-80 w/cruise on, 2 adults, no cargo, no special driving techniques. We got 33.4 mpg, including a bit of city driving, mostly freeways. I'm pretty happy, our last vehicle (Grand Caravan) would have gotten about 25mpg on that trip. My wife drives the vehicle for work, short trips, stop and go, she gets about 23-24 in daily driving. '07 2.2 auto, no mods except synthetic oil.

 

https://www.chevyhhr.net/forums/fuel-economy-hypermiling-47/absurd-mileage-17070/

 

I am just starting to get a mileage base line. Very few of my tests have been with air conditioning off and they were short runs so not very accurate.
There was 7 MPG better with the air off in one test so it may be very significant. This is Texas so it will be in the middle of winter before I do much more testing with AC off. I am curious to know if anyone else has experienced such a big difference with air off. I am not giving up my air conditioner even if it is 7 MPG. Hopefully it is only about 1.
My mileage has been from 22-24 city driving, 37 MPG @ 60 (44 with AC off), 29.5 @ 70 and as bad as 26.3 @ 85 MPH.
For the testing I treid to make it as simple as possible and eliminate human element. Just got it up to desired speed, set cruise control, reset DIC and run it 20 to 25 miles to stabilize then record it along with weather and any other notes. I also tried to do the same 25 mile run each way on the same day to eliminate as many variables as possible.