The A/C drops mpgs in city driving also. I've owned my HHR 19 months and am getting 24 mpg this winter. It's usually 21-22 mpg in the summer.

Wind and hills have a significant impact on highway mileage. I experienced it driving north from the Florida panhandle up I-55 then south on I-65 for the return trip. But, I would much rather have less mpgs in the HHR than struggle fighting the wind in an SUV or mini-van. I did that for too many years.

Yes, gas mileage will increase as the HHR get broken in. Be patient. It will happen!

 

Ok Mr. Snoopy, I did a test today. I went out on Interstate 70, and drove 23 miles. I went 23 miles one way at 66 MPH, and came back at 71 MPH. Here are the results:

65 MPH = 32.2 MPG

71 MPH = 28.8 MPG

I will test it again on a long trip along Interstate 95 soon.

I will also share this: On hilly route 27, between Mt. Airy, Maryland, and Germantown, Maryland, without driving hard (avg speed 40 MPH), the MPH was 28.2, up and down hills.

Peace,

MWG2

 

Just did the calculator on mine and I got a really lousy 22.7! I rarely let my hhr warm up for very long never more than 5 mins. Highway trips are hardly ever above 70 MPH. Is this just winter taking its toll or should I look into getting an appointment at the dealer?

Oh by the way, it is a 2006 2.4L auto with 20,000 miles.

 

So MWG2...

You didn't say. Are you happy with that reading?

But of course, a 50 mile trip is not a good representation of overall mileage. One or 2 tanks of gas (close to 1000 miles) is a better example.....and probably more accurate

 

dr_fosg8, 22.7MPG might be lousy, or it might not. Is that city, highway, or mixed? How quickly do you take off from a stop? Do you run the front defogger much? (the defogger turns on the A/C if it's over 32 if I remember correctly). 22.7 doesn't really sound that bad, because if it's cold(<20F) and I leave the HHR outside, that's about what I get for mileage in mixed driving. If it's over say 35, I will get 24-25MPG on the same trips.

 

You would be surprised at the increased economy of drafting. If you were in the lead in the HHR, then the Toyota would would not be spending as much energy to be traveling the same speed.
The NASCAR folks here could explain in further details. Just don't do any of that "bump drafting"!

 

Back when I had my Bonneville SSEi (3.8 liter V6 ,supercharged) and when I had my Grand Prix GTP (same engine), I could pull those 28.x numbers at 75+, and both cars were a heck of a lot faster. It's just at the city speeds those cars were not so efficient, getting around 20. My combined mpg was around 23 'ish most of the time. Of course, the trunk vs the space in the HHR is a totally different equation, and I could have bought two 2LT HHR's for the price I paid for the Bonneville (seriously). So, the money I saved on the car itself will pay for a lot of gas.

It's not a 4-cyl vs 6-cyl thing, it's a weight, rpms', transmission thing. I think that if our HHR's had an extra gear, they could cruise a little more efficiently at those higher speeds, but the higher weight of the transmission would hurt a little at the lower speeds.

 

Just have to put in my 2 cents. Some of you are talking about what lousy mileage your HHR gets. Sure my 2LT is new and running on winter gas in snow country but getting above 22mpg sure is wonderful to see and the dic goes above 26 on a long stretch of road is money in my pocket when the Ram I just got rid of would during the winter be getting 13.5 if I were lucky. I can't haul 2000# in the HHr but my hauling days were coming to an end in more way than one, I loved the looks of the HHR and got one and could of gotten a Toyota or something else. It seems that we have all forgot that we or most of us bought it because of the style and if you want better mpg, then go get a Yaris or Smart car for that 35+mpg then don't cry that there is no room in it for your wife and kids and the dog. When you compare the HHR to others cars, it is still listed as one that gets better mpg than a lot of other cars, in the mean time just enjoy what you have as most of us do.

 

Yes!

But MPG is not the reason for purchasing the HHR. I just love the car. I love the looks, the cabin, everything. As my friend last night said, "Barry, you are a retro man." I even keep XM on the 50's station.

 

so...did we determine:

in the author's HHR:
did you use the defrost at any time during your trip? How about the Highlander?
The defrost activates your AC compressor, which will drop your mileage.

also...consider the horsepower to weight ratio. If the highlander has a V6, and road conditions requires some grades, or mild acceleratrion, the V6 might have more torque, and require less 'go pedal' to reach cruising speeds.

Personally, I'd sacrifice a slight difference in fuel mileage to drive a HHR, than a Highlander. Consider all the reasons why you bought a HHR...if it was for fuel economy only, there are other vehicles that do better. But they lack the style, fun factor, handling, size-benefit, practicality, and many other features.
also, cruise control does not save fuel. You can feel speed fluctuation up slight grades....all cruise control does is give the driver a rest. I have always been able to get better fuel economy with my right foot vs cruise control, in all of my cars.

Just a few of MY observations-not fact, just opinion.