tech question

[Jake Sternberg]

E85 is 85 percent ethanol (regular corn drinkin' alcohol) and the other
15% is gasoline.  water is not part of the recipe.  regular
gasoline-fueled cars have been converted to E85 by changing nothing but
the injectors, and the oxygen sensor has been very happy with this.

i don't understand why this is, because it's true that the mixture for
E85 is something like 7:1 instead of 14.7:1 like for gasoline, but
apparently the oxygen sensor doesn't care about that, it just cares about
the amount of leftover oxygen.  i mean.. that's all an o2 sensor measures,
right?

-jake