I was gloating only a little. I feel that the 2.4 is more "peppy" I suppose as compared to the 2.2, but I do run 93 octane only. I think all GM Ecotec cars that aren't "SS" or sport tuned have some sort of anemia off the line, I believe its due to the economical and conservative gearing and stock tune. Even my 2.4 can seem gutless at times from a standstill. Acceleration while moving however is phenomenal in my opinion. Performance from a stop is also enhanced while in "I" instead of "D", but the vehicle also shifts much harder in that mode with the intent that you will be going faster I think. I didn't know anything about Ecotec before I purchased my HHR, and not to gloat or sound rude, but I am very glad I went with the 2.4, at least on my 2006.

 

Your not going to notice 6 hp and 2 lb ft. Probably just the difference in 2 cars. For the autos, they did have a final drive ratio change to a higher ration after 2006, but that would have made your 07 actually feel slower, but many panels got the original ratio.

One reason I went with the 2.2 and the 5 speed, performance numbers were almost identical to the 2.4 auto.

 

It's hard to say why one is more responsive than the other. Maybe the '06 was abused, or the '07 may have better compression. Maybe the '07 has had the transmission fluid changed a few times along the way.

 

We have a 09 and a 10 2.2 in both. The 10 has more power then the 09, it is enough difference that my wife noticed it when driving the 10. The 09 is hers and the 10 is mine. As to off the line acceleration both seem pretty good, as there several people around that have been surprised with their squirt ahead to jump in front attempt fails and they end up behind, and yes I am bad I then do the speed limit because a lot of time they have been tailgating to try to get me to go faster.

 

Based on personal experience, '06 models are a bit lacking in "Oomph" off the line compared to the '07-'11 models, for the reasons stated above.

But an '06 will "wake up" nicely with a few tweaks, like a GMPP or equivalent intake, a GMPP/Borla/Magnaflow "cat back system", and a tune such as a Trifecta Tune.*

*Although Trifecta has been reported to have stopped "supporting" their tuning for the Ecotecs used in the HHR's, I've not received confirmation on this from Vince at Trifecta.