The blend wall—the percentage of ethanol to gas considered safe for car engines—is 10% or E-10, and past efforts to create and push E-15 have failed. The little-known practice of automakers quietly voiding warranties on cars whose owners use E-15 gasoline illustrates the industry’s understanding of the harm that levels of ethanol passing the blend wall (E-10) causes to car engines. Triple A also warned against the use of E-15 gas in pre-2012 cars. Not only are engines—cars, boats, lawn mowers, chain saws, etc.— harmed, but ethanol blended into gasoline, not just the higher E-15 blend but even that at the blend wall, also contributes to a loss of mileage. …
The EPA is now moving to raise the level of ethanol blended into the majority of the nation’s gasoline past the “safe” E-10 blend wall.
The Environmental Protection Agency’s move to add more ethanol to gasoline will wreak havoc on lawn mowers, snow blowers, boats and even cars, say critics.
Mixing an additional 700 million gallons of ethanol and other biofuels into the nation’s fuel supply to meet a goal of 18.8 billion gallons in 2017 will raise the biofuel percentage to 10.44 percent, or past the “blend wall” after which car engines can be damaged, said Heartland Institute research fellow Isaac Orr.