cowdog

Well.

I average just about 30 MPG with regular gas, mostly freeway driving. I now have 11k miles on my 2010 2.2L Flex fuel HHR which I bought May 5, 2010. I've used Arco regular gas until today...

I filled the tank with Chevron Supreme (91 octane) in La Mesa CA, it took 13.6 gals, then drove to Anaheim CA, 102.1 miles. I set the cruise to 58 MPH... ending DIC 42.8 MPG at my front door.

I've never achieved this sort of mileage before. Once, and only once, I got 38 MPG but it was on the reverse route, which always shows better mileage than coming back home. I also didn't go over 55 MPH to get that.

I believe I could do just a bit better than the 42.8 MPG, but not much, and it would then be just a game and a lot of work. I'd have to lighten the car by not having any luggage, prob lose some weight myself , only have a few gallons in the tank, drop my speed a bit, etc. Even with all of that I doubt it would improve any more than maybe 2 mpg, if even that much.

I have seen a big improvement in using higher octane, but 100 miles probably isn't the fairest test either, I will see how the rest of the tank and the next fare on mileage.

fatphil

18 to 20 mpg in the city, 24 to 26 on the highway with the cruise on and no more than 5MPH over ( 2008 2LT 2.4L with 18,000 miles). I truly feel there is a problem with the tune as I get slightly over 30mpg in my 05' Lesabre driven in the same manor! I can't help but think my car is like the portion of other 2.4L HHR's on this board that have some odd problem with fuel economy! Tune Time ???