Spec blending to get 87 octane is mentioned.
Actually that was the part of Fuel Methodology that I do remember reading:
Quote:
"The decision to use RG as the blend stock for ethanol
blending, rather than HO, was based on real-world trends in
that ethanol is unlikely to be blended with high-octane
gasoline. As fuel ethanol consumption increases in the US,
there is a trend away from splash-blends toward matchblends,
which use a blendstock for oxygenate blending
(BOB). In splash-blending, ethanol is mixed with a finished
in-spec gasoline, whereas with match blending the ethanol is
blended with a BOB that is formulated for the specific
purpose of ethanol blending. One of the intended purposes of
BOB is to reduce evaporative emissions by reducing the
vapor pressure of ethanol fuel blends. Importantly, since
ethanol also acts as an octane improver, the octane number of
BOB doesn't need to be as high as conventional finished
gasoline to meet market specs. Because producing a high
octane product is more expensive for refiners, the BOB
blendstock is likely to be of a lower octane than conventional
gasoline. Thus, the ethanol fuels for this study were blended
with the lower-octane gasoline."
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It doesn't mention mixing with a lower Octane Gasoline so maybe they just used regular 87? If anything I would imagine this blending stock would be 85 Octane or so.