**GAO-11-513**                      Published: Jun 03, 2011. Publicly Released: Jul 08, 2011.                  

-   
-   
-   
-   

    Jump To:  
-  Elder Abuse 
-  Services for Older Adults 
-  State and Local-Level Drivers and Trends 
-  State and Local Fiscal Projections 
-  Federal Borrowing 
-  Managing the Debt 
-  Summary of Funding Provisions 
-  Auditing the Government's Books 
-  Unpacking the Financial Report 
-  Highlights 
-  Recommendations 
-  Background 
-  About This Work 
-  About This Work 
-  Trends 
-  About the Center 
-  Why It's High Risk 
-  What Remains To Be Done 
-  Key Reports 
-  Newest COVID-Related Reports 
-  AI Use Cases 
-  Flood Insurance 
-  Past Pandemic-Related Reports 
-  CARES Act Oversight Reports 
-  All COVID-19 Reports 
-  Report Suspected Fraud 
-  Subjects 
-  How to Get Notified 
-  Past Reports 
-  Public Health Threats 
-  Explore the FY 2022 and 2023 Funds 
-  Lessons Learned 
-  Agency Reports 
-  Recent Reports 
-  Recommendations 
-  Supplemental Material 
-  Full Report 
-  Additional Data 
-  View Decision 
-  Downloads 
-  Previously Identified Actions 
-  Related Pages 
-  Associated Agencies 
-  Tough Choices and Opportunities Ahead 
-  Americas Fiscal Future Key Areas 
-  Retirement Security Key Areas 
-  Current List 
-  About The High Risk List 
-  Area Ratings 
-  Previous High Risk Products 
-  Search Federal Vacancies 
-  Past Federal Vacancies 
-  Violation Letters 
-  About the Yellow Book 
-  Advisory Council 
-  Related Resources 
-  Comment Letters 
-  Related Publications 
-  Contacts and Resources 
-  Major Issues Facing the Nation 
-  Meeting Strategic Challenges 
-  Additional Resources 
-  Resources 
-  GAO Contacts 
-  Mission Teams 
-  Operations and Staff Offices  
-  Organization Chart  
-  Why a Career at GAO? 
-  Am I Qualified? 
-  Company Culture 
-  Reasonable Accommodations 
-  Video Gallery 
-  Paid Internships 
-  Student Volunteers 
-  Professional Development Program 
-  Advancement 
-  Executive Candidate Program 
-  Summer Associates 
-  Externships 
-  Benefits 
-  Contacts 

Skip to Highlights

## Highlights

U.S. transportation relies largely on oil for fuel. Biofuels can be an alternative to oil and are produced from renewable sources, like corn. In 2005, Congress created the Renewable Fuel Standard (RFS), which requires transportation fuel to contain 36 billion gallons of biofuels by 2022. The most common U.S. biofuel is ethanol, typically produced from corn in the Midwest, transported by rail, and blended with gasoline as E10 (10 percent ethanol). Use of intermediate blends, such as E15 (15 percent ethanol), would increase the amount of ethanol used in transportation fuel to meet the RFS. The Environmental Protection Agency (EPA) recently allowed E15 for use with certain automobiles. GAO was asked to examine (1) challenges, if any, to transporting additional ethanol to meet the RFS, (2) challenges, if any, to selling intermediate blends, and (3) studies on the effects of intermediate blends in automobiles and nonroad engines. GAO examined government, industry, and academic reports; interviewed Department of Energy (DOE), EPA, and other government and industry officials; and visited research centers.

## Recommendations

## Recommendations for Executive Action

## Full Report

Highlights

Full Report (57 pages)

Accessible Text 

## GAO Contacts

Frank Rusco
ruscof@gao.gov

(202) 512-3841

## Office of Public Affairs

Sarah Kaczmarek
kaczmareks@gao.gov

(202) 512-4800

## Topics

Natural Resources and Environment

Air pollutionAir qualityAlternative energy sourcesAlternative fuelsAutomobile industryBiomass energyEnvironmental monitoringEquipment managementFreight transportationFuel consumptionFuel salesFuel storageGasolinePollutantsPollution controlRenewable energy sourcesRenewable natural resourcesSafety regulationFuel research