I should have followed my advice. Always telling people “read the manual”. Been putting 87 octane in our new 2007 2LT auto. Should have been 91 +.

Plus side the wife loves it. We looked at Element and Scion XB. She didn't see the HHR until I got it home. She likes it more and more everyday
.

 

I know it has been discussed ad nauseum (sp) here, but does it really make a difference what octane you use? I've had Blackie for 7 weeks now and 87 is all it has had...feels fine to me and I get about the mileage I'm supposed to be getting.

 

A lot of the owners with the 2.4L use 87 octane, the computer will adjust for it and GM also says it will work. Some guys say they get a little better mileage but does the extra cost offset it? Plenty has been discussed on this forum as to the use of 87 or 91 in the 2.4. You are not tied to the 91 octane since GM only recommends it, not requires it. I'm sure more of the member will tell you the same.

 

Although I have used 91 octane since day one, I agree with other members that 87 or above is also acceptable. I think more important is the fact that you want to use a high quality top-tier or equivalent fuel. Also as a sidenote-for the protection of your fuel pump, try to avoid letting your tank, at least on a regular basis, from dropping below one-quarter full. This prevents having the pump in certain situations "run dry",that can eventually cause it to fail.

 

Hi All,
I've had my new 2.4 2LT w/auto for about 6 weeks and 1400 miles. I feel that running premium since about 500 hundred miles has made a differnce in mileage and power. I don't like spending more for it, but I'm getting the most from the 175 hp engine that way. Where I feel the differnce is at the 1-2 shift point. The car has more sack than when I was using 87. Maybe the motor is just breaking in. Either way I'm very happy with the Ecotec motor.

 

The computer will adjust timing with fuel grade. More octane, more advanced timing. It feels like more power, but it just allows faster acceleration to a point.

Never ran 91 Octane, may not. I'm ok with how my 2.4 runs and drives on 87

 

Anyone know Who sells 91 in Florida? Shelll and Mobil sell 93. I don't mind paying more we put 93 in the Corvette. We only put 6,000 miles a year on each car. I think I'll do 1/2 tank 89 then 1/2 tank 93 and see how it runs.

 

I used 91 octane until my first oil change. I have since put in 2 tanks of 87 octane. My observations so far:
91 octane gives me close to 30 mpg
87 octane gives me close to 27 mpg
it seems there is a wee bit less power with the 87 but a small change. I will use 91 every few tankfuls. My last fill up yeterday I put in 87 octane with 10% ethanol...will see how that goes.

 

i too have noticed better milelate with 91, 2-3 mpg.

 

The Z family loves the Element, all wheel drive good on gas and a lot of room. So I purchase one for my wife she loves it. So I have the HHr and she has the Element. Hey I have put 87 Octane in mine since the day I purchased it, No problems at all.

Rudy