What am I missing here?

I thought rust, rubber and plastic deterioration in the fuel linings and systems were significant enough issues with ethanol that many manufacturers PROHIBIT using more than a 10-15% ethanol mix. And they will VOID coverage on warranty issues if excessive ethanol-use was considered the cause.
SOME newer cars (flex-fuel and others) allow any % of ethanol. But many new cars (and almost all older cars) still specifically mention avoiding a high percentage of ethanol.

Steve

STOP terrorism - Drive a HYBRID

Vehicles:
350 miles a week ------------ 2006 HCH II, Magnetic Pearl, w/NAVI (born on May 25, 2006)
350 miles a month ---------- 2003 Mazda Tribute ES-V6
350 miles a year (for now) - 1986 Mercedes 560SL