Super Unleaded
 

Does anyone use Super?? Will it really hurt my 5.4L if I use it.

Why would you want to use it unless you have a tuner. Your engine was designed to run on 87 octane. To use other is a waste of money and will get you no better performance.

Exactly. Unless your tune requires it, or have spark knock (which sould be repaired anyway), don't use it.

The Only Reason I Want To Use It Is Because I Can Get It For Free...... And I Cant Get Regular Unleaded For Free. That Is Why I Am Trying To Find Out If It Will Hurt My Truck

It won't hurt your truck. If it's free, use it and share with us how you get free gas.

Stealing gas from work isn't free:smoke:

it will in no way HURT your truck if you use a higher than recommeded octane level. You will not see any gains from using it, but it will not hurt your truck either.

If you engine isn't optimized for use with premium fuel, like with a tuner or something, there's no sense in it. You'll actually get a little worse performance and fuel mileage.

In general, run the lowest octane fuel you can get away with.

Explain to me where you can get free gas, I would like to know that one since my truck requires high octane fuel. :coffee:

as mentioned previously it will hurt perfromance. whether or not it is noticeable is debatable.

the higher the octane the slower the burning

cmon ppl. read everything before you reply. i think you went and frustrated the guy and thats why he isnt replying.

he obviously doesnt care about performance. all he wants to know is if it will hurt his truck or not. if i got free gas i wouldnt care if i got 2 mpg.

it won't hurt your truck... it should run better and keep your engine cleaner bc of the additives in it. i spoke to a mechanic about it a while back bc i was hearing alot of diff **** about it.

There is no benefit. It won't gain you anything. I will burn cleaner, resulting in perhaps less deposits over time, but the expense outweighs the benefit:thumbsup:

everyone freaks out about the expense. have you calculated what you are saving by getting the lower octane gas? like 2-5 bucks per fill up. big savings eh?

We need an engineer to chime in here.

From the limited research I have done over the years I have learned that it will indeed harm your engine.

On the contrary it will in fact cause MORE deposits due to the fact that it burns slower and the engine has no way of knowing that there is slower burning fuel in there. Therefor the timing is not adjusted properly so in turn you get excess carbon build up.

Other than that I believe it is harmless to use it.

my .02

peace-

I have to admit, I've wondered about this before. I leased a 2001 Ranger w/ the 4.0 Liter SOHC v-6 a few years ago. In the owners manual, in BOLD CAPITOL LETTERS it stated "Do Not Use Fuel With Octane Rating Greater Than 87. Doing So May Void Your Warranty."

It was also boldly printed on the gas cap to only use 87 Octane fuel. Consequently, I never put in gas rated at more than 87 Octane. I have no idea what the warning was all about, or why running a higher octane could possibly cause damage, but that is what the factory manual said.

Since then, I have never seen such a warning again, with the expections of vehicles that required premium fuel, such as my old '96 Z28. My current truck (1999 F-150, 4.6, 4x4) simply says optimized or some other such word for 87 octane. No warnings at all about running anything higher.

Any thoughts?

Mike

:confused:

yeah, that 2-5 can mean a lot to some people... i fill my tank atleast twice a month. so thats up to $10 a mo i could save?

Heck, I fill mine twice a week.

if the vehicle says don't run it then don't run it but if it doesn't then go ahead...
I'm right there with you.
well from what my mechanic told me (who has alot of experience) he had a ranger that he ran nothing but premium on and after 400,000 miles the engine finally went out. he said when he took the engine apart it was clean enough to eat a steak out of because of running the premium gas. not trying to make an argument, i could be wrong, could be right or visa versa. just throwing something in that someone that experienced told me about.

Here are a few pages of very good info about fuel. some of it is very technical.
www.faqs.org/faqs/autos/gasoline-faq/part1/

If it's free, by all means use it! :bandito:

Using too high octane fuel does ruin the engine, but it does ruin the cats. Higher octane fuel burns slower, so unburned fuel is sent out the exhaust manifold. Since your not burning all the fuel, you would get lower fuel mileage, but since this fuel is free, who cares. Problem is, the unburned fuel will destroy the inners of the cats. If you have a short lease, or live in an area that doesn't test, then burned out cats verses free fuel seems to be the real cost question.

i get it from my wifes parents.......... they have gas stations and use Super in their vehicles, at the end of the year they write it off as a business expense. So i can get super for free and they just write it off like they were using it. its hard to figure out whether to use it or not everyone says something different.

Dont remember where I heard it, or read it, but using super in and engine designed for regular will foul the converters because of all the unburned fuel.

Octane is an additive to CONTROL the burn. Some believe that octane is something to make the gas have more energy. No! Octane rather allows a
crankshaft engine to extract and use more of the available energy in the gas. Injecting water into the intake manifold has been used to boost octane rating.

Remember that all gasoline fuel has an octane rating. All gasoline crankshaft piston engines are dependant on gasoline design burn control.

Some engines need to burn the gas slower than others. From what I've read , you guys prolly already know this , good thread..

This is 100% true. Newer vehicles with more sophisticated computers can tell when you are burning premium or regular, and the computer varies the timing and other factors to compensate. In older vehicles, the computers were not designed to do such, so there is no benefit. However, even if the chance of cat damage exist (and I'd bet its so minimal you could win the lottery first) you would still be better off getting free gas. A couple of aftermarket cats would only set you back a couple hundred bucks, or the equivalent of maybe a months worth of gas. I'll step out on a limb and say you'll never have a problem.

Unfortunately, many people assume that higher octane fuel is better for all engines, no matter what. This, as I'm sure you know, is absolutely false. Ultimately, the best octane for any vehicle is the lowest one you can run without detonation (pinging) occuring.

Running too high of an octane will ultimately make it necessary to continue using that octane.

Just to clarify, it's not the fuel that increases the performance, it's the fact that the timing has been advanced. The higher octane permits this to happen. Basically, the way it works is something like this:

Octane represents a fuel's stability. When you compress an air fuel mixture, it becomes quite unstable, and explosive. In fact, this is why diesel engines don't require spark plugs. They commonly have compression ratios of 22:1 (as opposed to a stock Mustang with 9:1), which makes the air/fuel mixture so explosively unstable that it ignites itself when the piston reaches TDC.

Octane, for all intents and purposes, is used to slow down, or control the burn rate. Modifications that increase performance, such as increased compression, or advanced ignition timing, will cause the mixture to become too unstable, and pre-ignition (aka: detonation, pinging) will occur. This is when the mixture fires on it's own, at the wrong time. Severe damage will occur if left untreated. Anyway, the only way to perform the mods that increase the power is to further slow down and control the burn rate of the air/fuel mixture, and the method used to do this is increased octane.

People often think of high octane fuel as being more flammable, and easier to ignite, whereas that is actually the opposite of the truth. 110 octane race gas is much tougher to light than low grade 87 octane. BUT, because of that fact, it is the use of 110 octane fuel that permits the compression to be increased to 12:1 without melting the pistons.

Use of a fuel that has a higher octane than is required by the engine and the way it has been tuned will result in unburned deposits being created and left behind in the combustion chamber, and on top of the pistons. These deposits cause the combustion chamber to become very unstable, for several reasons, all of which will ultimately require you to use a higher octane fuel to restore stability. Among the reasons, are increased compression (the deposits take up space, and actually increase the compression over time enough to make it unstable), retained heat (deposits retain heat at times when those surfaces shouldn't, increasing the likelyhood of pre-ignition), and the development of sharp edges (like sand under the waves, deposits can be "shaped" by their environment, and can develop sharp edges, which act to the compressing mixture like a hat pin would to a balloon.

I believe the only way a vehicle can "Tell" if there is high octane fuel is if it has a knock sensor. Someone smarter than me needs to answer whether these trucks have them or not.

Please feel free to correct me if I am wrong (I know you will!) but there are no other sensors that "Tell" if you have put a different kind of fuel in the tank. ECM's don't have the ability to change timing based on what kind of fuel is in the tank. Though it would be cool if it did!

Think about the logic of this thread's question: If it were as easy as some have stated here then why are there engines that require it and ones that don't? If we follow this logic we should just be able to use what fuel we want and the ECM will take care of it. But that isn't the case.

More proof lies in the fact that amoco had to pull its ads about its high test increasing power and performance because it just isn't true.

In addition, a clean engine is not a good case study. A clean engine from fuel is based on the additive package not the octane rating. Yes some brands put more addatives in the the higher octanes (IE: BP/Amoco) but most put the same engine cleaners in all octanes.

Here we are questioning the engineers who designed these engines for 87. This should be added to the oil arguement: Is it safe to use 10w-30/20w-50 because my grandfather did 30+ years ago or because an old fasioned mechanic says its ok.

Oh well maybe and engine designer/engineer will read this and set us all free!!

Peace-

Yeah , on top of the block under the plenum - I believe all 97 -03's are - Idunno past that.. Neals got a good shot of it in his motor build thread..

The octane rating has nothing to do with how clean the combustion is.
The additive package is designed to adjust the octane rating for those engines that need it .
The PCM and hardware setup on ''these' engines (not some other make), measure the rotation time of each cylinder as a way to monitor missfire and general power contributuoin to the overall power of the engine.
It is this area where the engine becomes sensitive to rotation time that a more conventional engine design will not be.
Running an octane that slows combustion time will affect the rotation time and result in no long term benifit.
You can't get around the software and the hardware design just changing octane of the fuel.
Stay with 87 unless there are pinging problems not due to malfunction or fault.
Or use a tuner capable of advancing the software timing to take advantage of the slower combustion time so the 'peak' cylinder pressures occurr at the same point after top dead center as with stock timing and 87 octane..

i notice a diff when i goto shell and put v power in my tank... my truck seems more responsive and a few extra mpg... may not make sense from what the responses are to this post. just throwing in my 2 cents