I use 87. I found thar higher octane made little mpg difference except made my wallet lighter.

 

I use 91 exclusively.

 

The most I've been able to squeeze is about 450 out of a tank, but that's driving between 55-60 on the highway with the cruise on. This car is 6 years old and that was about a month ago. I've only run 91 or higher since I bought it. No complaints here.

 

I wish I had a longer trip to make sometime, I feel like I could easily squeeze 500 miles out of a tank in my HHR with the 2.4, but my trips never take me farther than 300miles. I use GOOD 87 octane from Shell..exclusively.

 

Friday did a road trip, "fill-up" to the "ping" of the low fuel warning.
Only 410 miles It was all freeway around 70-75 mph, but really windy.
So only got 28.47 mpg

When I drive highways 55 -60 mph I can usually get 31+

The extra speed and wind really cut the MPG down.

626 miles you must have run it to a rolling stop, out of fuel?

 

well i am getting ready to take my first cross country trip on our 09 2.2 auto. we normally pull it behind our rv. we get 28 or so around town

 

I'm taking mine down to Tucson for Christmas, and that is goin to be the first long haul I've taken in it. I normally get around 23-25 in the city, stop and go 'n everything. I know it went down a bit after I put the new exhaust on it, mostly because I like the sound of it when I'm in it. but since then, the lowest Ive gotten is 24. I have the cold air goin on in a couple weeks. and after that I'm doin headers and I'm trying the 2.4L manifold on there. I know the bump in HP will be nice but I'm tryin' to make this li'l 2.2L breath as well as it can.

I do notice that when I am rolling along at 70 with the cruise off I get about 30-31 instant MPG according to the cluster, but as soon as I hit the cruise it jumps to 33-34.I can get almost 40 MPG with the cruise on at 65. Keep in mind a mountain here in north Texas is an ant hill anywhere else. its F-L-A-T!

 

Second tank: 628.6 miles, 15.057 gallons. Meaning 41.75 mpg. DIC said 40.2.
Again, keep in mind, I have a 5-spd, a VERY favorable commute (rural highway at 50-55 mph), high altitude and I'm an experienced hypermiler (I used to get 47 mpg out of my 5-spd Pontiac Vibe).

 

I'm impressed 5speed4, but every once and a while, drop down two gears and stand on that sucker....all mileage and no fun makes for a dull day.

 

I've seen 14.7 MPG after a spirited run around town.