If a fuel additive in the amount of 8oz per 128 gallons was enough to show remarkable engine improvement, the epa would have mandated it long ago as all of the ingredients are available at the refinery.
I don’t know about your 1:2000 (or so) ratio, but I know that 1:125 and even 1:250 ratios of additives can be useful. Alcohol certainly can improve the performance of a vehicle that has water in the fuel at the rate of 1 ounce per gallon or so. But does that mean it should be mandated therefore in all gasoline? (It does in fact attract water vapor which can also be a bad thing.)
Specific additives can be a good thing for specific circumstances. I would hate for EPA to mandate them when they are in fact often not helpful at all and even detrimental.
