The banning of antismog additive MTBE (methyl tertiary-butyl ether) presented a new challenge.

FORBES: On The Cover/Top Stories

Also helping the business are environmental mandates (depending on where it is sold, some gasoline must contain up to 10% ethanol as an antismog measure) and energy independence mandates.

FORBES: Whoops

Also helping the business are environmental mandates (depending on where it is sold, some gasoline must contain up to 10% ethanol as an antismog measure) and energy independence mandates (national use of ethanol must meet certain minimums by various deadlines).

FORBES: Ethanol: Payback Time