Many States do not provide 93 octane. The highest is 91. Because you are driving x country, you may encounter this. If you use the 91, I would be interested to know if you experienced any recognized loss of mileage and power.

 

I've had my 07 2.4 LT auto for about a month now. I am one of those crazy agressive woman drivers. I commute 110 miles round trip for work. It's mixed about 40miles of city driving/ 70miles of highway. My highway driving is 3-5 mile open stretches at about 85 mph and then 2-3 miles of bumper to bumper between 55-80 mph. City is total stop and go betweeb 35-55 mph. According to my display, my MPG hasn't gone over 26.0 mpg. It stays about 25.7 or so. I think thats pretty good considering I drive like a maniac. For your mileage to be that low something has to be wrong.

 

I did a short day trip to Augusta GA on Easter, I left with about a 3/4 tank, I filled on the way back, the DIC showed 540 miles till empty..... This was using highway (60mph) roads verses interstate (70mph) roads mostly.

 

I have the same here...... i have the 2.4 bought my hhr had 12 miles on it. It has 8000 on it now, the most i have gotten 26 on the hiway driving right after i bought it. And if i am lucky i might get 20 in town driving.. its worse if you use the remote start..... thats the only thing that disappoints me about the hhr. I bought my daughter a 2007 cobolt she is getting 27 around town.... i have tried both 91 and 87 no difference. runs just the same with the get up and go

 

Geeze, my 2006 HHR stock gets average 25.7 city, and 30 highway. I use regular gas. Haven't really noticed a difference in cold or warm weather (well, excluding a/c). I'm happy with the milage, of course, I traded in a Ford Ranger for the HHR, and that was getting 14 - 16 mpg.

 

I use the 93 octane. I know mine is capable of getting 30 mpg. Right after I got it, the injectors had to be replaced. When it was done, the dealership drove it down to me from Arcadia to Naples. When I got in I checked the DIC, 30.6 mpg. The courier was an old guy and it was highway pretty much the whole way. He told me he couldn't believe how great the mileage was on the trip. I know my lower mileage is because of the way I drive.

 

i just took a road trip today from Kansas City Mo to Rogers Ark. manual calculation was 25.2 on the dic was 23.2. Still not happy with the milage. I really wanted 28 to 30. Drove with cruise on a steady 75 mph Talk with service today and they told me they would do some checking (what i dont know) when it goes in next when the recall part shows up.

 

Would getting the dealer to re-flash the computer do anything to help?

 

I dont know if K&N makes a drop in filter for the HHR yet, but I just dropped in a K&N filter into my 2.4 G5 and saw a huge difference already with accel and MPG. cost about 52 shipped and is woth it so far(only 170 miles on it)

 

Yup, they do. From NAPA the part # 33-2339 was $53 shipped.