I guess being lucky or crazy enough to have a sampling of them from '06 to '11, I can tell you that the mileage is pretty much the same for all the ones we have. Across the board I see 25 mpg in mixed driving with an average of 31 mpg on the highway.

 

Correction ..... 2.2L went VVT in 2009

From Motor Trend Magazine ... 2008


For the 2009 model year, Chevrolet is adding a "blank canvas" Panel SS version to the HHR lineup aimed at giving performance minded customers or business owners the best option in expressing their "automotive creativity." Also revised for the upcoming model year is the base 2.2-liter Ecotec engine that is now outfitted with variable valve timing. The resulting unit is modestly bumped by six horsepower to 155. Flex-fuel capability in its 2.2-liter and 2.4-liter four-cylinder engines is also now available on all LS and LT models, further aiding in fuel economy.

SF

 

2006 LT and a 2008 SS, both are about 25mpg combine driving. City and rural country roads.

 

I guess there is no gain with the VVT engines then? I wonder why they added it if nothing was gained except more complication?

 

They may have gone to the VVT 2.2 engine just to standardize the manufacturing process. The 2.2 runs 87 octane while the 2.4 may run 87, 89 or 93 octane. I run 87 in my 2.4 with no ill effects.

 

Just filled mine up for the first time after the free dealer tank. Got exactly 29.4 MPG went 392 miles and took 13.4 gallons. Not bad at all for very city centric/service based miles (driving around town getting new tires/wheels installed, picking up cleaning/detail stuff, a few grocery & refreshment runs along with two 25+ mile round trips). If it stays in that territory and hopefully does even better with some real serious highway miles I'll be very happy.

I did decide to try E85 for the new tank fill as it was under $3/gallon and I want to know what kind of change it gives on the MPG. Got to do the math to see if the $$ savings is real or not. Plus the ethanol based fuel is supposed to keep things cleaner so I want to see how it goes. Post an update when I have the results.

 

I know this isn't a definitive answer, since they used the VVT on the 2.4 prior to the E85 vehicles from 2009(?), but I've always felt that at least a part of the reason for the change to the VVT was so they COULD run the E85. Let the computer adapt the timing to whatever fuel was being fed to the engine.

 

I've been getting 28MPG in Winter, 32+ in Summer

Earlier this Summer I was only getting ~30.5 but I've been getting about 34 since I changed the air filter.

I have ~320 miles on the current tank and DIC reads 34.5 avg mpg.
Granted that's mostly highway with about 100 miles of secondary and very little city but I'm psyched for 34.5

That's including a few passing boosts @ ~90 & 95.3 MPH but mostly 70 MPH

The sweet spot seems to be ~70 MPH



BTW - always 93oc usually Gulf or Hess with some Sunoco & some Shell - 10% ****, no alc-free 93oc around here

 

Here's what I typically see when I fill the SS gas tank

 

The EPA passed stricter fuel economy standards in 2008, causing fuel economy estimates for all 2008 and beyond cars to drop about 1-2MPG. So if you compare the EPA milage for a 2008 car compared to an identical 2006, you will notice they are different.