Ok, so we're all agreed?? NO!! YES!! Our HHR's deliver somewhere between 20 to 32 MPG depending on engine, transmission, driving conditions, A/C and mileage. Hmmm, Chevrolet & the EPA estimate 23-30mpg. Pretty close and they are on the high side, no?. So what really gives?

I'm an owner of an "06 HHR LT 2.4L auto, CGS Intake, 9000 miles. I bought the car new with 1600 miles on it so break-in may be a contributing factor, but in the last 5 months, my gas mileage has gone DOWN!!! I now get 19-21mpg average 70/30 (City/Highway) and max of 27 on the highway (75-80mph). Now I live in Houston and we use the A/C 300 days a year, so I understand that is an issue. When I run without A/C my milage picks up 5MPG!! I also have one of the A/C units that whines like crazy!!! Sounds like a "tuner" exhaust!!! Yuk!!!!! (I'm working the dealer to get it replaced)

I've heard that reflashing the ECM can help. What I'm looking to do is have someone re-flash the ECM and TCM (for A/T vehicle). Our automatics are NOT well tuned for mileage or performance. I have asked Hahn Racecraft about it.

And our "fly-by-wire" throttle needs serious work. I drove a '07 2.2L and the throttle response blew me away! There has to be some kind of adjustment that can be made. It's got to be just a "pot" (potentiometer). Anyone out there have any other ideas?

Our HHR's are just too cool to be gas guzzling slugs!!!

 

Popi.....

Your highway mileage of 27 is probably about right at the indicated 75-80 mph you drive. The MPG curve will drop substantially and proportionately, after about 2500 RPM......you are probably running in the 3000+ range.

If you are recognizing a reduction of 5mpg when using the a/c, you probably have something wrong. GM tests have supported generally a 1-1.5 mpg reduction.

For example, on a recent 7000 mile vacation trip, I used the a/c exclusively (sometimes with the sun roof open, sometimes just adjusting the temp control). I averaged about 31 mpg for the entire trip, traveling at whatever the posted speed indicated....55,60,65,70,75. Also used the cruise control exclusively except for some heavier mountain grades....I manually shifted to "I" drive.

 

Off topic,

You were at FedFleet in 2006 in LA? Me too.

 

I found out on a trip to DC that Premium fuel makes a dramatic difference in Fuel economy. on regular unleaded 28mpg by paper and gauge. 34.5 on premium 32.7 paper a significant difference. IMHO Now I have to figure out if price of gas here is worth it to me.

 

Yep, I was there in the GM booth.

I have not tried premium yet, but I took a 100+ mile trip from So.Cal. to Bakersfield over the grapevine (moutain range) with the cruise set at 70mph I got 33.6 mpg on the DIC going there and 31.4 on the return. Hit a lot of traffic due to the truck crash that closed the 5 fwy.

Not sure that premium fuel here would make that much of a difference as we have oxygenated fuel all year round and we loose MPG with it.

 

I just bought my 2007 Chevy HHR IN July and in august i went on a 1,000 mile trip and i was getting 32.4 mpg at 75-80 mph. Putting around town i have been getting around 26mpg

 

Well congrats to all of you LOL, I do 90% street driving, and get a little less than 19 mpg. I don't really mind too much because a little quirk about my work is that I get a $100 gas card a month and that pays for all my gas. However I will be making my first road trip...going from So Cal to MO. so I will finally get to see my MPG on a long trip, will fill you all in when I get back, Todd (Uma)

 

2 weeks ago ran from Canada to Daytona Beach for my vacations (still there) and got a 35-36 mpg with 2.2 5 speed with ac on. Very proud of my HHR

 

Canada to Florida. That's down hill!

I just drove my 2.2 automatic from North Georgia to cental Illinois and back.
70-75 mostly with a/c. Didn't do as well as you, did average 31.8. I was happy with that.

 

I was running 65 mph lower rpm means better economy .