Summary of High-Octane Mid-Level Ethanol Blends Study

Global Biofuels at the Crossroads: An Overview of Technical, Policy, and Investment Complexities in the Sustainability of Biofuel Development

“…Vehicle design improvements could allow for mid-level blends of 20%-40% to be used with enhanced efficiency. This is in contrast with that seen currently with the flex fuel vehicle operating on E85 (i.e., 85% ethanol blend), though at somewhat reduced efficiency [24].…”

“…These features translate into less pollution and generally fewer miles per gallon compared to petroleum-derived gasoline, if produced with methods that minimize emissions. In most regions, ethanol is used as a fuel additive in gasoline at roughly 10%, rather than a total replacement [3,17,[21][22][23][24][25]. Brazil is a notable exception, where the fleet of flex fuel cars operates on any blend of gasoline and ethanol or solely on ethanol [1].…”

“…Specific to ethanol, the fuel economy translates into a reduction of 25%-30% in fuel miles per volumetric unit versus gasoline, whereas for biodiesel, the difference is less (relative to diesel). If mid-level blends of biofuels are used at 20%-40%, octane benefits can be derived without much energy penalty of the higher blends, though engine and vehicle design changes are required with investment in infrastructure [24].…”

Effects Of High-Octane E25 On Two Vehicles Equipped With Turbocharged, Direct-Injection Engines

“…3,4 Several recent publications have shown the potential efficiency benefits of high-octane fuels in boosted, direct-injection engines 5,6,7,8,9,10 . Improved vehicle efficiency combined with the use of renewable feedstocks such as ethanol can provide attractive well-to-wheels greenhouse gas benefits 11,12 .…”

“…When 25% ethanol is blended into sub-octane BOB, the resulting high-octane fuel has a minimum RON of 98 14 . Many prior studies examining the octane-enhancing benefits of ethanol have focused on 30% ethanol blends (E30) 3,5,6,7,11 . The purpose of these studies is to demonstrate, at the vehicle level, the benefits of splash-blended E25, when the base fuel is Tier 3 E10 certification gasoline with minimum 87 AKI.…”