My concern was mostly with the iridium electrode. Seems to have burned away compared to the new ones. As far as the red additive, that is strictly a color used for off road fuels, it is used to determine if a fuel is tax exempt. all fuel additives must meet certain regulations and most of them are BS. all fuel must meet minimum federal standards and it is heavily tested, additives are more of a marketing scam than actual performance issue. Yes, after 200k miles there may be a difference but I have run 99% ARCO gas with never an issue. Working in a refinery for 24 years gives me a little insight.