Alcohol can be more than for emissions
cleaning the combustion chamber
winterizing and absorbing water
cutting detonation allowing more compression or boost
did you read the link for a basic understanding?
You can get more POWER (horsepower) with added alcohol but for a shorter period of time
less ENERGY less MPG
My experience is with Methanol not Ethanol
Corn lobby does not help
we had
twin turbos and 50 lbs boost
over 1000 reliable horsepower from 210 cu in 6 cyl stock block 30 years ago
lots of advances in anti corrosion have been made
Big advance now are high pressure electronic fuel injectors for diesel and direct injectin
The "eco-boost" type results are amazing
lots of compression and lots of boost
what's not to like