DOE Reports Intermediate Ethanol Blend Test Results

Since August 2007, the Department of Energy (DOE) has been testing intermediate ethanol blends, primarily E15 and E20 in conventional vehicles and smaller off-road engines to determine possible impacts on durability, drivability, and emissions. The tests were conducted on 13 popular late-model vehicles and 28 small non-road engines, including lawn equipment and generators.

Vehicle results include the following when E15 and E20 were compared with traditional gasoline:

• Tailpipe emissions were similar;
  
• Under normal operations, catalyst temperatures in the 13 cars were largely unchanged;
  
• When tested under full-throttle conditions, about half of the cars exhibited slightly increased catalyst temperatures with E15 and E20, compared to traditional gasoline; and,
  
• Based on informal observations during testing, drivability was unchanged.
  

Small non-road engine results include the following when E15 and E20 were compared with traditional gasoline:

• As ethanol content increased:
  
  • Regulated emissions remained largely unchanged,
    
  • Engine and exhaust temperatures increased;
    
• Engine performance was inconsistent, even with traditional gasoline;
  
• Commercial engines, as well as more sophisticated residential engines, exhibited no particular sensitivity to ethanol from a durability perspective; and,
  
• The effect of E15 and E20 on the durability of smaller, less expensive residential engines (e.g., line trimmers) was not clear given that a number of these engines failed regardless of fuel type.
  

Source: DOE Press Release