i don't know where you folks are getting your numbers from but here the spread is at least 10% on the price of regular versus premium. If you are going to provide facts so others can make an informed decision please try to keep them accurate. Wild guesses and wayward opinions don't help anyone. Reading this reminds me of my neighbor who insists the nissan truck he just bought gets 33 miles to the gallon when everyone else with that model gets 18. I've run 87 octane in my c280 a few times and I haven't noticed one bit of difference in performance or gas mileage. Maybe I'm the lucky one and my car is just ambivalent, or maybe the little dance ritual I do before starting her up is the charm.