I have about 2200 miles on the 2.4 now and just started my second full tank of 92 after about 4 tanks of 87.

I must say there IS a difference in performance. No lag during shifts (auto) now. Noticable pep when starting out and I think I'm getting better mileage. Although that's hard to say due to the fact we had a nasty little 100 degree heatwave here last weekend and I ran a mix of city/city highway trips with the air on and still averaged 24 MPG. During the previous 100 degree heatwave I was only getting 22 MPG.

So far I like it. I willing to give up the $3.00 extra on a tank to get the performance.

 

What sold me on using 91 grade, beside the fact that it will produce more thermal btus, has a cooler combustion burn, a cleaner burn with a better burn pattern. When my "dic" went from 387 miles with 87 octane, to 434 with 91 octane on the first tank of higher octane, that is a significance improvement in performance for $3.00 more dollars. Not to mention that the engine and xmission are a little crisper with the higher octane fuel.

 

Well as much as it hurts the old pocketbook I decided to give high test a try and I went from 21 mpg to 27 with a mix of city/hwy with the edge toward city. Soooo I guess premium it is.

 

I feed the beast only shell v-power 93. I couldn't tell you if it had more or less power than lower octane, but I have 1200 miles on it and took a 200 mile trip and pulled 33.4 mpg according to DIC. The 2.4 seems very happy with the 93 :)

 

I get better mileage and more oomph with 92 than i did with the lower grade fuels.

 

i use regular

 

I use 93.

I didn't think the HHR was one of the Flex Fuel vehicles. Am I wrong? Does it burn E85?

 

I have always used 87% since I've purchased my HHR I paid $1.94 a gallon for fuel this evening in Hessville IN.

 

I was using 89 for the first 2 months of ownership, but I didn't even know that a higher grade was recommended...I started using 93 (shell v-power!) and I have noticed better acceleration and gas mileage...I will now only run the highest grade available!

 

I use 89 in my hhr, but i couldnt see a diffrence from there up. But when i do run 87 its alot more sluggish. Ive tried a few different stations and came up with the same results. So when my wife drives it and put 87 in, i follow up by topping off with 90 something (93 or 94) and give it a shot in the arm.