Ethanol may be added to gasoline to achieve a number of goals.
Designation: E (for ethanol) + (percent ethanol)
Example: E10 is 10% ethanol, 90% gasoline.
Example: E100 is 100% ethanol, 0% gasoline
Common ethanol-fuel mixtures: E5, E10, E15, E20, E25
Ethanol flex fuel has between 51 and 83% ethanol and is suitable for a flex fuel vehicle. E85 was the former designation of flex fuel.
Negative effects:
(1) lower energy potential vs unaltered gasoline (95-98% for each 10%)
(2) damage to seals, pistons and other engine components
(3) more rapid degradation
(4) water absorption
Positive effects:
(1) cleaner emissions
(2) less dependency on foreign oil sources
