[vatdevil]

I would be more concerned with the ethanol in the 93 than the ethanol free lower octane 87. Ethanol based fuels can over time phase seperate. That means the upper layer loses it's ethanol and this lowers the octane level in it. The lower layer becomes ethanol rich along with whatever water it absorbs. Ethanol doesn't stay mixed with gasoline very well, but loves to combine with water, So make sure to add an ethanol stabilizer.