Asylum_Doc

Yes, I did reset everything except the oil on the DIC. However, here is what I found when I filled up to come back from Iowa. I had 360 miles on the trip ODO, around 40 of that was in town driving with heavy foot. My DIC showed 21 MPG AVG. However, it took 14 gal to fill and that was squeezing every drop I could into the tank. That comes out to 25.7 MPG. So, I don't think the DIC is real accurate. I got 29 MPG on the way back home, same route, same speeds.

solman98

I just did a 350 mile trip this past weekend. Reset DIC at fillup prior to trip. Cruise set at 76, two adults, one child in car seat. Small amout of cargo. 95% was interstate and cruise on at least 80% of the time. DIC said 29.7, actual was 28.6. This was no A/C.

My DIC always says more than it actual is..........

HHRANDY

We have filled up 31 times over the past 10,865.1 miles, using 319.317 gallons of premium unleaded gasoline. Doing the math, we are averaging 34.0 MPG, consisting of mostly highway driving, not exceeding 65-70 MPH.

The average DIC readings over the same period is 32.77 MPG.

That equates to a DIC error of 3.75343%.

Our mileage has definitely dropped off considerably now it's getting colder. The 34.0 MPG appears to be dropping by an average of 2-3 MPG.

I can say driving at speeds greater than 65-70 MPH will really impact your fuel mileage in a big way.

Regards,

HHRANDY

pitbull76

Our 2LT 2.4 rarely gets over 26MPG on the highway, and averages 22 in mixed daily driving. A rental HHR 1LT W/2.2 I drove once for work averaged 29 on the highway, running the same speeds that I do with ours. Mileage appears to vary by engine size or a bit from car to car.

Alzonie

I've noticed over the last few weeks that the Chevy dealer here in Chandler has been advertising '07 HHRs and claiming "34 mpg". I don't know where they came up with that figure 'cause last year when we bought ours I believe the figure was 30 mpg Highway. Where did that other 4 mpg come from?
Or is that just hype!!

solman98

It's just a typo.

CHV_FRK

DO NOT TOP OFF YOUR HHR.

Where the vacumm canister is located you will pull fuel into it and ruin it. Come on guys, if a 1/4 or 1/2 a gallon is going to keep you from where you're going you driving the tank too low anyway. Fuel cools the pump. For longevity, you shouldn't go much below 1/4 to an 1/8th of a tank.

Heritage07

You'll get a slight increase in mpg if you use 89 octane mid-grade fuel, rather than 87 octane regular. 89 is also better for your engine.

Those who are running at 75 mph on the interstate and getting somewhere in the mid-20's mpg, shouldn't complain. The EPA rating of 30 highway is based on the car traveling at the posted speed limit, which on most of the stretches of interstate I've been on, is 55-65.

Drive 65 on shorter highway trips like going to work, 70 on the longer trips such as out-of-state vacations, and you should be pretty pleased with your gas mileage.

calgaryhhr

I ran into a similar feeling of disappointment on a trip this last summer. I bought the HHR because it looked cool but also thought it would be great for trips because of the room in the back and the 4 cylinders. Before this I used to do my trips in a 3.8L V6 Chevy Impala. Well when I found out that I had better gas mileage on the same trip the year previous, with the same amount of gear and weight, in my Impala as compared to the HHR I was shocked.

I was hoping for better. I personally think that the HHR would see a great benefit from a 5 speed automatic. I think the 4 speed on the highway has something to do with poorer economy than expected. Wind drag is a problem for sure. Tire's might have something to do with it as well. Wider and more performance oriented tires apparently provide more rolling resistance.

That trip provided some useful insight though.

sleestack

The milage on the hhr is good but not something out of this world. Back in november I bought a 96 impala ss (5.7 liter engine). I pick it up about 170 miles away. Right before we got on the expressway to come home I filled up the impala at a station and reset the HHR computer.

We drove back at the same speed. The results was 26 mpg on the HHR and 24.8 for the impala. Not a big difference especially when you consider how much bigger the impala is, with a little work you could fit the HHR in the trunk. In the city is were the bigger engine losses ground, 14.7 aveage vs. 20 for the HHR.

For the difference in mpg I perfer the imp, it a hell of a lot faster too.