For the 5.4, what octane are you using and how is it?

Is everyone using 87?

 

SUNOCO 104 octane with a pinch of jet fuel

 

Cheapy.

 

i better read my owner's manual before i have to fill up tomorrow...

please God, let it be 87 octane required. i don't want to pay for 91...

octane ratings, from the way i understand it, do not affect an engine like ours. high performance sprts engines, like a BMW, require the gas to burn quicker and therefore need the higher octane. on our trucks the electronics controlling the engine would adjust to have the right timing since hte fuel will burn at a different rate, but it wouldn't carry any advantage to run high octane fuel in our engines. i am not claiming to be an expert, so anyone is free to refute me, but that is how i understand it from friends and from www.howstuffworks.com.

cheers.

 

According to the manual both the 4.6 and 5.4 require 87 octane. It also says using higher octanes may cause difficulty starting, rough ideling, or hesitation while driving.

It's also interesting to note that they recommend not using fuel additives.

See page 245 of the manual to read what they say.

 

Mine's chipped but runs exclusively Chevron 91 octane. That's all the better we get in Utah.

 

Actually just the opposite is true. Octane is mearly a measure of gasoline's resistance to pinging (pre-detonation.) Higher octane results in gas with a lower energy content and a slower fuel burn. High performance engines, such as a that in a BMW, run a higher compression ratio than say a F-150. That higher compression will cause low octane gas (which is more flammable,) to ignite before the spark plug lights the cylinder...effectively turning the engine into a compression ignition engine (i.e. a diesel.)

So go with what the owners manual says, 87, any more is just a waste of your money. While running higher octane may not harm your engine, it doesnt do it any good. Some engines will get carbon buildup in the combustion chamber which will cause the driveability problems that breser noted; difficulty starting, rough idle, or hesitation while driving. This really doesnt harm the engine in any way, and it can be easily cleaned out with some special cleaner.

Repeat after me..."I will not waste my money on high octane gas. I will not buy into the gas station's claims of "Premium" gasoline. I will only put in the gas that is required by my truck."

Do this several times, maybe even make a tape to listen to while you are sleeping at night.

 

I would have to agree with MN4x4 on this as I have gone through all of this before with my ATV's. Sounds like he is right on with the experience that I have had.

 

One tank so far and I am using 87 octane. The manual recommends 87 minimum.