i was worried about my ampgs my first couple of months i got my car... but i think after your first oil change, you'll notice your mpgs improve... i think it has something to do with the type of oil used to break the car in. but i can't be too sure, it improved a lot for me after the first oil change.

from my oil change:
first fill-up: 351.1 miles, 9.453 gallons = 37.142 ampg
second: 352.2 miles, 9.629 gallons = 36.577 ampg
third: 357.6 miles, 10.945 gallons = 32.672 ampg

for the 3rd fill-up, i wasn't really trying to save gas. just wanted to compare the difference between regular easy driving to driving in a rush, and pushing the pedal a little harder... haha!

 

Also need to factor in the driving environment as well. The EPA ratings are for vehicles in controlled driving environments - usually several trips down a relatively low-traffic interstate freeway, and stop-n-go driving in a low-traffic area as well. Keep in mind these numbers are meant to represent 'best-case scenario' driving conditions, therefore your mileage may vary when factoring in situational stuff.

If your spending a lot of time idling at stoplights, or in bumper-to-bumper traffic, you're getting zero mpg, which takes away from your numbers... especially with the A/C running. You can figure on the A/C compressor stealing roughly 5-6 horsepower from the engine (average) - not so bad when at cruising speeds, but on take-off it's huge.

Shutting off your engine (like a hybrid does) is not the answer - most damage to your engine internals occurs during start-up... mostly because engines don't come with pre-oilers, so you're starting almost dry in some instances. Plus, when the A/C core begins warming up without the compressor running, you'll roast before the light turns green.

I still think you might've gotten a car with a sensor that came from a bad batch. Be patient, and that factory recall may come along. If you really like the car (outside of the disappointment in gas mileage) I'd say give it a little time.

 

Civic EX '07 manual transmission (12 000 Km): 6 - 8 l/100 km depending on conditions.

Montreal - Boston with 30 l of gas a couple of weeks ago .... maximum speed 130 km/h

 

We have a 08 civic & just turned 2000 miles. Most of our driving is 50-60 MPH & we are getting tops 42 MPG. The tank before todays fill up gave us 36 MPG. I could not be more pleased with every aspect of the Honda.