Smoke Wagon

reason #1 I bought a different car: fuel economy
reason #2 I bought a 4-cylinder : fuel economy
reason #3 I bought my HHR: I love the style, the performance package, and the price....the fact that I can cover #1 and #2 with #3 is just amazing.

cheaper fill ups, more miles per tank, and nice to drive...I am amazed every time I drive it.

I have yet to tank up with 91 octane...soon folks...real soon. I am a perfect example of a "mileage chart"...I typically drive the same route, the same speeds, every day-5 days a week.

But ever since I bought the HHR, my routine has changed slightly...but soon it will go back to the way it was...and I'll have feedback.

sbljr

IF the manual RECOMMENDS 91 or above (never seen manual to the 2.4 but some members here have said it does) then by all means YES use it if you want full power! In modern EFI engines with knock sensing, those motors will "reprogram" on the fly for lower-octane fuel, giving up some power in the process. That's why it's acceptable to use 87 if you're in an area where you can't find anything else.

My BMW is the same way. Premium is "recommended' and it definitely loses power on regular (some skeptical owners have even had theirs dynoed to see if it's really true and it is, though power in that car is still abundant enough you don't notice it that much). OTOH if the difference is as pronounced as you describe, it sounds like you'd be defeating the purpose of getting the 2.4 option in the first place if you ran regular in it.

BTW where'd you get that cool "CHEVROLET" grill lip? I like that!

an08HHR

http://cgi.ebay.com/ebaymotors/Vinta...QQcmdZViewItem[/QUOTE]
This is what someone mentioned to me. It was posted in a thread in the appearance section yesterday. I ordered one also. Seems to be a big hit with us HHR owners.

cpendlay

It's about more than just power. When I first got my HHR 2.4 I used regular and it ran fine, after reading that I should be using premium I decided to give it a try and see how it affected my mileage. I was getting about 19mpg around town with the 87 and with the 93 my mileage jumped up to 25mpg around town. One the highway I get about 34mpg. I did some calculations and using the more expensive premium actually saves me a few cents per gallon since I get about 6 more mpg. Yes it hurts when I fill up but the overall cost is a bit less. When I first switched to premium I noticed about 4mpg improvement in mileage and I gained the other 2mpg when I tried top tier gas. I really did see a noticeable difference.

mynameistaken

wow those are big gains. So far I have only seen .5 MPG on average with premium.

zakandsandee

for those who may be interested, this is one of the least technical, easiset to comprehend explanations of octane ratings and when/why to use

http://www.straightdope.com/columns/041008.html

pretty basic but for non gear heads it's a good read

I'll have to check my manual, we've been getting around 22 average city and 30 highway (depending on which one of us is driving.. my daily driver is an old CJ so tend to get a led foot in the HHR) Our 2.4 is great on regular, I never dreamed it had the compression ratio/spark temp etc to get anything out of premium. for us it's just the wagon that can bark tires.. we've got a 57 T bird and a 80 corvette to play with when we really want speed.