High Octane Fuels: Challenges and Opportunities

The document examines the potential for mid-level ethanol blends (E25 to E40) to improve fuel efficiency and reduce greenhouse gas emissions in the U.S. transportation sector. It highlights that a significant portion of the existing vehicle fleet and fuel infrastructure can accommodate these blends with moderate costs. Research indicates that increasing ethanol content can enhance engine performance and that a nationwide E25 blend could reduce transportation GHG intensity by 5 to 9 percent.

• Mid-level ethanol blends between 25 and 40 percent (E25 to E40) can increase fuel efficiencies and lower overall greenhouse gas emissions for the existing passenger vehicle fleet compared to the standard 10 percent blend (E10).
• A substantial part of the current U.S. vehicle fleet is compatible with higher ethanol blends: over 80 percent of cars from model year 2001 and newer are certified for E15, and there are 17.4 million FlexFuel Vehicles (FFVs) capable of using blends up to E85.
• Infrastructure upgrades for mid-level blends up to 25 percent ethanol are generally less costly than those required for E85. NREL testing found that 56 percent of tested Underwriters Laboratory refueling equipment was compatible with an E17 blend.
• Using the GREET model, researchers estimate that a nationwide E25 blend providing a 5 percent fuel economy gain could lower the transportation sector's GHG intensity by 5 to 9 percent, while an E40 blend from cellulosic ethanol could achieve reductions up to 30 percent.
• The DOE's Co-Optimization of Fuels and Engines (Optima) Initiative aims to reduce per-vehicle petroleum consumption by 30 percent by 2030, which could save consumers up to $50 billion and reduce petroleum use by 4.5 billion barrels.
• Lifecycle GHG emission reductions for corn ethanol in the U.S. are estimated between 19 to 48 percent relative to gasoline, while cellulosic ethanol from corn stover may reduce them by 90 to 103 percent.

APA

Stolark, J. (2015). High Octane Fuels: Challenges and Opportunities. Environmental and Energy Study Institute. https://www.eesi.org/papers/view/fact-sheet-high-octane-fuels-challenges-opportunities

Chicago

Stolark, Jessie. High Octane Fuels: Challenges and Opportunities. Environmental and Energy Study Institute, 2015. https://www.eesi.org/papers/view/fact-sheet-high-octane-fuels-challenges-opportunities.

Wikipedia

{{cite report |last1=Stolark |first1=Jessie |title=High Octane Fuels: Challenges and Opportunities |publisher=Environmental and Energy Study Institute |date=12 June 2015 |url=https://www.eesi.org/papers/view/fact-sheet-high-octane-fuels-challenges-opportunities |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{stolark2015high, author = {Stolark, Jessie}, title = {{High Octane Fuels: Challenges and Opportunities}}, institution = {Environmental and Energy Study Institute}, year = {2015}, month = jun, url = {https://www.eesi.org/papers/view/fact-sheet-high-octane-fuels-challenges-opportunities}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }