So...if I've got 175,000 miles on my '07 G35x, avergaing about 20 mpg, I've put about 8,750 gallons of gas in my car over the past 10 years. Right now in Colorado premium is about $0.60 more than regular. If that's the case over 10 years I would have spent about $5,250 more on premium. ( I used to use premium, but have used regular over the past 2-3 years) I used to not care because the difference was about 10 cents - not sure why it's gone up so much lately. Yes, I know, I haven't really spent that much, but going forward probably would!

 

I'm staying away from anything that has ethanol in it. My second tank after buying the car I bought a premium gas with 10% ethanol mixed in. Power and MPG were both down. Also at 10.6:1 compression 91 is required to run the engine at it's full potential. You should clearly notice a difference on 87, either in performance or range.

 

Non oxy at BP here in Delano, Minn, is 2.99 a gallon, otherwise u can't find a station that is NOT oxygenated, plus, there are >seasonal< blends, LOL, for winter and summer!