E10 is the term for motor fuel blends of 10 percent ethanol
and 90 percent gasoline. All motor vehicles manufactured since the 1970s
can run on E10. E10 does not require any engine modifications. E10 is
required in Louisville and Northern Kentucky near Cincinnati. All of the
Big Three auto makers have recommended the use of gasoline containing
oxygenates, such as ethanol, in their warranty statements since the 1993
model year. About 30 percent of the nation’s gasoline contains ethanol—and
most of that is in the form of E-10 Unleaded. In some areas of the
nation, ethanol is blended at rate less than 10 percent due to
state-specific regulations. (On the other hand, some states are
considering increasing the standard blend to 20 percent ethanol.)
