27th Feb 2012, 12:09

I agree. Higher octane fuel won't make a car run better. That's been a long time myth. High octane is for high performance engines to eliminate the knock because it burns slower. A car designed for 87 should run fine on regular gas.

27th Feb 2012, 17:17

You have a car that is less than a year old and still under the manufacturer's warranty. You need to be more persistent, and as someone else pointed out, go to another dealership. Contact GM if necessary. There is no reason you should have to put up with this, because the techs can't figure it out, and you need to let them know that.

10th Mar 2012, 12:17

So many variables, who knows what they sell us at the pumps. Go with the highest octane available, and hope that's what they are selling you. If it is, you will pay more, but get better mileage and performance all around. Then take that car out and punish it, by putting your foot to the floor for a good run down the freeway for about 5 miles, and watch the black smoke you leave behind when your foot is pinned to the floor. CLEAN IT OUT MAN...