When they first started running oxygenated fuels in cars, ethanol & MTBE, it was damaging engines. Mostly eating the seals out of the fuel system. The automotive industry changed the problem materials and have mostly countered this, at our expense. Similarly, changes had to made to engines to cope with the removal of lead.
Now, we're running up food costs because we're driving on what we were eating. I also question how much good it's doing. Alcohol only contains about 85% (check out BTU/gal) the energy per gallon as gasoline, so we are paying more for a lower value fuel. On top of this, cars that have their engines controlled by computer (almost anything since 1985) see that oxygen rich exhaust and respond by making the air/fuel ratio as rich as possible. This is why your milage goes down about 10% when running on oxygenated gasoline. If you are driving something that is bordering on underpowered to begin with, you can also feel a "seat of the pants" difference in the engine power.