Automakers will need higher octane fuels to meet the coming increases in fuel economy and reductions in emissions called for by 2025, according to a new study by auto engineering firm Ricardo, Inc.  Octane is the standard measure of the anti-knock properties (i.e., engine performance) of a motor fuel.  Most fuels today, including E10 ethanol blends, have an octane rating of at least 87.

The increase in average fleet fuel economy to 54.5 mile per by 2025 will have to be met in large part by engines and vehicles popular today.  Ricardo notes, “[t]he vast majority of vehicles sold through 2025 in the United States will use gasoline-fuelled, spark-ignited internal combustion engines as the primary form of propulsion.”

Specifically, Ricardo reports that nearly 3 out of every 4 vehicles will require a gasoline-type, higher octane fuel to operate a growing list of engine technology options.  “Future powertrain solutions will have a natural thirst for higher octane fuels,” Ricardo concludes.

At a blending octane rating of 113, ethanol and higher ethanol blends are uniquely poised to help automakers achieve stricter fuel economy and emissions requirements.  While most measure a fuel’s mileage based on British Thermal Units (BTUs), new engine technologies designed to meet higher fuel economy standards like turbo-boosted, downsized engines will require the higher octane level that higher level ethanol blends offer. 

Coincidentally, the Auto Alliance has also recognized the need for increased octane and the potential for ethanol to help meet this demand.  In comments to the U.S. Environmental Protection Agency on pending vehicle and fuel guidelines known in the industry as Tier3/LEV III, the Auto Alliance noted, “to help achieve future requirements for the reduction of greenhouse gas emissions, we also recommend increasing the minimum market gasoline octane rating, commensurate with increased use of ethanol.  Adding ethanol to gasoline increases its octane rating.”

“Increasing fuel economy requirements across the U.S. car fleet presents opportunities for high performance, high octane fuels like ethanol blends,” said Bob Dinneen, president and CEO of the Renewable Fuels Association, which commissioned the Ricardo study.  “Rather than being limited to lower ethanol blends like E10 or E15, a thirst for octane from these new engine technologies could open up options for higher blends and be a boon to markets for ethanol-blended fuel.”

An executive summary of the Ricardo research is available here.  The whole report can be read here.