Ok, so I went ahead and filled up with this good stuff on Friday just to give it a try. A had asked a mechanic friend about it and he said the labelling is just as we thought. It's just a state regulation to try and keep emissions down. He said it is more than safe to use. Anyways, the car seems to run a bit smother with it and feels like it might have a bit more up & go. My mileage findings are preliminary but interesting. I've had the car about a month. First two tank fulls were 87 octane. My driving habits are pretty consistent (home to work and back, groceries, ect...) with it being about 70% in town and 30% highway. With the 87, I was averaging 32.5 miles to the gallon. Pretty happy with that. Then I decided to try some 91 octane (not the stuff in question but the standard 91 with an ethanol mix) for two tank fulls. It did feel as if it ran a bit smother, but my milage during those two tank fulls dropped to 31.7. Now it has only been two days with this 91 without ethanol, but my milage has jumped up to 33.8. So it is certainly liking the good stuff. It is odd that the 91 with ethanol actually decreased the milage a bit.