I have a 2007 2LT with a 2.4 litre engine and an automatic transmission. I have 32,000 miles on my car and rarely drive in conditions conducive to good fuel economy. For example, I live in Mankato, MN which has lots of hills and stoplights and, when I do highway driving, it's mostly on the interstate with a load that consists of 6 guitars and two amplifiers. According to the DCI, over the past 3,000 miles, I have gotten 28.2 miles per gallon! I think that's quite good given my driving conditions.

I have had 32,000 miles of trouble free driving with the HHR. After having two problem prone Malibus (a 1997 and a 2001) I must say I love the HHR's reliability. Yes, indeed, I love my luxury mini-Suburban!

 

It is surprising the MPG these HHR's obtain, I have 08 2.4 2LT, and average around 29 to 30 mpg on my weekly drives.

 

Mine is a 2008 and I have made a bunch of mods, 2.4 intake, Airirad filter, 2.4 exhaust W/ cherry Bomb muffler, taller tires, lowered and front air dam. Right now I am getting about 24-26 in the city and 32-34 on the highway at 70-80 MPH. I think it would get 38-40 at 55-60 MPH but I cant drive 55.
I definatly like the mileage but I think it could even do better with the right mods.

 

Mine is a totally stock 2007 2.2 auto and I average 34+, I've seen 47.7.

I'm glad you're happy with sub 30 but I wouldn't be. The 3.1 V-6 auto I had before never got less than 30 in over 3 years.