I'd agree, 4% gains for 3-3.50/gal vs, basically c16 price at 88 per 5gal isn't worth it, but there is crappy places out there with %70 or lower instead of the 85 they are claiming, that will mess with afr and tune should prob be adjusted for each tank's quality of ethonal
as for his claims of corrosive, there are plenty here running it daily for years and injectors/fuel pump are fine, I have no idea about the lines, and im sure it depends on where you are for how fast you'll see something negative from pump e85
its amazing how many people are seeing better results with e85 vs top dollar c or q16, its like 1/4-1/5 of the price