Not sure what you're referring to, dc, but here's where I got my info:
From: http://www.shell.com/home/Framework?siteId...ls_ga_0111.html
Shell Regular and Plus gasolines, which meet the “TOP TIER” standard, also contain more than two times the amount of cleaning agents required by the EPA. Shell V-Power goes even further – it has more than five times the minimum amount of cleaning agents required by government standards and twice the cleaning agents required by the “TOP TIER” standard.
Actually, I said their regular grade had 3x, when it's actually "more than two times." I got the premium grade right, though.
And from: http://www.bp.com/printsectiongenericartic...ntentId=7013479
In terms of cleaning formula, Amoco Ultimate meets the Top Tier program specifications.