I now that the dealers and manuals recommend regular gas, and I have a question for you guys, not sure but the Regular gas is supposed to have less additives than the Premium, according to what is said, right? Well I used to work in a gas station for some time and every-time we compare the three kinds of gas, the regular gas was always darker in color, like brownish, yellowish, and always stinks, the premium was always a lot more transparent, I do not now if any additive that cleans the color of the gas, making it more transparent, all the opposite. All of them are darker, how is that possible? Also and not sure why but the regular gas is always more dirty, like more opaque...and all the cars that usually use regular gas, the gas filters were always a lot dirtier than the ones using premium while replaced in our shop...
On my old Taurus, a 2000, with 125,000 miles on it, but still working very nice, with regular gas the knocking is really noticeable, with premium, dead silent, something is going on, not sure why? It seems that not all regular gas is the same along the US, or maybe it is not stored with the same care as the more expensive ones...BTW they reco also regular gas on the taurus....