HipHotRod

As some of you know, my 08 2.4 auto is getting ridiculously crappy gas mileage. Im lucky to get mid 15's around town. So today I had my first freeway trip.

So..
2.4 auto
36 psi in the tires.
Went from long beach (405-605-210 fwys) to Laverne Ca. 106 miles round trip
Av speed was 70Mph

DIC is reading 24.9 MPG

Something is definately not right with the car to be getting such horrible mileage. My DOHC 350HP Marauder got 15 around town and 26 on the hwy.

Any ideas?

GRUMPEE

Sounds still a little low, but not bad.

My all time best was with light traffic on my trip to Vegas I avg'd 29-30 (DIC) & 26-27 (DIC) @ 70MPH with 4 people +luggage. I was on cruise control 95% of the time

On my way to the Feb G2G, my DIC stayed around 28-29 in the Camp Pendleton stretch, but as the traffic got heavier I had to get off the cruise control, so it went down to 26.

1) When I first got the HHR I did a comparison between mileage with regular and premium gas - at the time the mileage seemed better with a tankful of the higher octane stuff. So even with the high cost of gas I still tankup with premium (the higher mileage offsets the 20 cent/gal diffent in price..so far)

2) Once on the freeway and up to speed I reset the fuel econ setting to get a pure highway mpg

3) the more I use the accelerator (more frequent speed modulation) my highway avg goes down. However during local driving for safety I'm less apt to use cruise control.

4) Remember the HHR is not aerodynamic.

afs9

You know Don, I can't seem to figure out what my mileage is either.
The dic says I get about 18 mpg and that I average about 16 miles per hour driving--that I know isn't right!

When I fill the tank, I always reset the 'trip'. If I go by how many miles I have driven in say "trip A", when it gets from full to the first 'notch' on the gas gage and divide that by 2 (I assume that is 2 gallons??), I get about 22-25ish mpg. The original car sticker says 23 city, 30 hgwy, but has different #'s of what you actually will get: 19-27 city, 25-35 hgwy.

I get so many different readings of how many miles i get per tank, I never know what to believe. I show anywhere from 298 to 395 per fill up.

This is all stop and go traffic with the occasional freeway trip in OC--never have used cruise control.

I actually watch the approximate miles left as it does seem to change up or down according to how I drive.

I have a conference in Monterey coming up and was going to drive--I'll use that to see how my highway driving is (and finally use the cruise control!)

Not sure if that helps...

mitzkity

I get about 16-18 at best just tooling around town. But have got up to 30 on the freeway. I have heard, however, that you won't get the best mileage unless you use premium gas. Do you think there's any truth to that??

JimZ_HHR

Lately, I have been resetting my DIC (MPG, AVG MPH) on each tank, I use 87 octane, each fill up, it has been about 30 - 35 avg MPH, and on average about 23 MPG.

wingfeather

...

afs9

I've used premium gas a few times and don't notice any difference in mileage. Certainly not enough to quantify paying almost $4 a gallon for it.

But I do notice a difference in performance if the gas is ARCO (cheap gas--my sister swears it is 'water') and say COSTCO.

Nor-Cal HHR Club

The dealer said when we bought ours in September 2005 that we would noticed the advertised gas mileage over a period of time as the engine broke in. Now whatever the reasoning, it has. We're getting better than advertised Highway mileage and the City mileage is right on.

Maybe the builders in Mexico slacked-off after the original 2006 Models. Who knows!

HipHotRod

Im happy for you guys that are getting at LEAST close or better than the advertised mileage. It is very hard to accept a 4 cyl, regardless of the DOHC, whatever is getting 15-16 mpg in town in my case. Granted I didnt buy this car for MPG alone or else I would have gotten some God foresaken Yaris. At the 2k miles mark, its going in to check for ECM updates. Also, what possibly could GM have done so drastically different in the 08 2.4 than the 06 2.4? As I mentioned and I will shut up about this, my V8 marauder got the same mileage as my brand new 4 cyl HHR. Doesnt make a lick of sense.

TkHHR

Don, What is your avg MPH say. I think what is killing you are the short trips. My avg MPH is 22mph (fairly slow) but that is an average. Almost every time I start my engine the mpg drops a tenth, then when I sit in bumper to bumper on the way to work it doesn't help either. I avg 21-22 mpg with mostly short trips and lots of traffic. If I get on the freeway and go a longer distance the mpg will climb. My best recorded mpg so far was 28.5 on a trip to San Diego a few months ago. I drive with the DIC set for MPG so I can watch it since day one and I think I have a better understanding of what it takes to get better mileage out of the HHR. Jack rabbit starts for one thing can make it go down in real time. I tend to coast whenever possible too. Now 21-22 isn't as good as I was hoping for, but based on where I drive it is, what it is. To get better would take long cruises with constant speeds being maintained. Bottom line is short trips kill the MPG.