Some outboard motor manufacturers disagree with your "facts".
Outboard motors can range from $2,000 for a small fresh water motor to $20,000 each for 300 HP motors used in salt water. Many salt water craft use two motors for safety sake for a total of $40,000.
After plunking down 40 grand you get a Owners Manual that says:
(1) Gasoline containing alcohol {methanol (methyl), or ethanol (eithyl)}, acetone or benzene, may cause:
*wear and damage to bearings, cams, piston(s), piston rings.
*Corrosion of metal parts.
*Deterioration of rubber parts or plastic parts.
*starting, idling and other engine performance problems.
(2) Do not use gasoline that contains more the 10% ethanol or more than 5% methanol.
(3)Damages resulting from the use of gasoline's that contain alcohol ARE NOT COVERED under the limited warranty.
Your loyalty to your home corn growing state of Iowa is admirable, but no consilation to me if I am dying of hypothermia in 50 degree water because the outboard won't run.
I dont know why you would buy a $20,000 boat motor with plastic fuel line parts. I wouldnt.
As I said, this is just an excuse to void the warranties. Save millions of bucks that way.