On the same topic of gasoline. Most mfgrs state in the owners manual that a minimum Octane rating of 87 should be used in their engines. So why do some states eg. (Wyoming and Montana) advertise and sell regular unleaded at 85 octane that the mfgr. says don't burn. The midgrade is 87 octane which in my area is regular. I won't burn 85 octane in anything I drive and am forced to buy the higher priced mid grade. How is it oil companies in these states can sell a product that car mfgrs say not to use? Am I missing something?