channelbass

Given that most of my thinking capacity is clogged with matters metalurgic as they pertain to shipbuilding, I have to take a shortcut to thinking and just ask...running 92 octane instead of the 87 prescribed in the manual(2002 5.4 S-crew) is actually detrimental to the engine and emission systems? Manual also states that "a little knock" can actually be normal...

To touch on another matter in that sticky, name brand (top tier) fuel suppliers, which is everybody's favorite brand? I was told by a friend in the petroleum industry that shell, despite all the TV hype, actually has one of the better quality fuels on the market?

Any thoughts or facts out there?

JCP281

running a higher octane gas in your car/truck/van w/e doesnt help you if you dont have the timing advanced accordingly to burn that gas. The higher heating value of the higher octanes requires a longer burning time to completely burn. Your making your emissions system recycle that unburned fuel and excess nitrogen more than you would if you had your prescribed octane in the gas tank.

Now, this is sort of offset by the better detergents added into premium gas. The cleaners are better usually in the premium octanes so they will theoretically clean your fuel system and engine deposits. I call BS to those claims tho lol.

My petrol of choice is shell, chevron. My Mustang runs best and I find I can run a little more timing with out pinging at high rpm as opposed to other fuels brands.

channelbass

Thanks for posting back, I do find I get about 30 mi more per tank with shell, don't know if that's for real or if my right foot is messin with me. It seems to go against the grain to think of higher grade fuel not always being better, but thats the problem with thinking along the lines of popular sentiment for so many years. I managed to extract some good info from the combustion sticky and it even forced me to think of the whole thing on a new level. While a good portion of it made my brain cramp up, I am glad I read it.