Ford tunes the engine to run on 87 because that's the least expensive choice at the pump, it doesn't mean it won't run better on something else. The PCM is adaptive, it'll learn and adjust accordingly to get the best performance and MPG possible. All a tuner really does is widen those parameters to give the PCM more room to adjust.

 

If my memory serves me right, from what Bill and Troyer have said for the past 4 years, that is not correct. All I have read is that it must be tuned for the higher octane to take advantage of it. That the timing is off for the slower fire of the higher octane. That it really does not hurt anything, but unlike precomputer days, you get no benefit.

There are multiple settings other than timing. Otherwise you could take one tune and adjust the timing up or down to whatever octane you are running. I have an 87 Performance tune and a 93 Performance tune and there are substantial differences beteen the two.

Just a side note, when I bought my 2000 Expedition, the dealer told me that I would be damaging the cats if I ran anything higher than 87. I do not know if they knew what they were talking about or not. I have never heard that since.

 

If the engine can ajust for different mixes of fuel on the fly then wouldnt it increase peformance? as an example if you had half a tank of 87 and half a tank of E85 then wouldnt the engine ajust to suit the fuel mix? I dont know to much about this sort of thing but if the engine can sense and ajust fuel type then something must get affected either a powergain or a poer loss depending on fuel type?

Oh yeah and by the way i noticed a difference months ago when i come back from SC and filled my tank with premium from shell. I thought i was dreaming but engine felt more powerful and smoother. There's a thread on here about it back about 3-4 months ago. There was def a difference.

 

All 2009 5.4's in the F150 are FFV.

 

The other thing to note here is that the difference between 87 and premium is more than just octane. Premium gas will be made to a higher spec and be cleaner and might even have additional additives.

 

You mean on a tuner site they would tell you that you are wasting your money unless you have their tunes!

 

I didn't say that tuning wouldn't be necessary to optimize the benefits of higher octane fuel. Did I? Wait, let me check.............nope, never said that.
What I did say is there's no harm in doing it but any perceived (I'll say it this way) performance/MPG gains will be offset by the increased cost of 93. The PCM will learn and adjust to make the most of whatever fuel is being burned, albeit within the very narrow parameters inherent to stock programming.

 

There are 2 sides to this. True it may not offset the cost of waht ever perforance gain there may be, but Shell & Chevron from what I heard put a higher concentration of additives in there high test fuels. So if I use any of these better top tier fuels, it may be a benefit to spend the additional .25/gal.

 

I'm reading in your post #16 that the PCM will adapt and give better performance and MPG. This I do not believe and what I was reponding to. I believe you will get essentially the same performance and in the earlier 3v can even be adding the dreaded carbon deposits on the plug shank as I don't think the fuel burns as completely.

 

...more gasoline myths.

Consumer level gasolines are not manufactured at different octanes. The gasoline is delivered in bulk from the manufacturing facility to the distribution facility. Based on many parameters, the additives that set the octane and distributor specific additives are calculated and mixed with the gasoline as its loaded onto the tanker for local delivery. All the base gasoline comes from the same bulk tank.

In my area, all the local gasoline for much of the West Central Coast of Florida comes from the same Shell distribution facility located in Port Tampa. Doesn't matter what brand is on the sign at the gas station, it all comes from the Shell distribution facility.

At the facility, the major brands such as Shell, Exxon, Amoco, Citgo, BP, etc.., have small tanks of their specific additives that are mixed as the bulk gas is loaded onto the tankers. The interesting thing the facility manager told me was, most all the additives are pretty much the same. The individual brands just have their own proprietary names for them. The government so tightly controls the contents of consumer level gasoline, there cant be much difference from one brands mix compared to another. Its all marketing hype.

Higher octane gasoline has LESS energy potential per a given volume than lower octane gasoline. Any added power associated with high octane gasoline is from an engine's ability to take advantage of the octane by either running high cylinder compression or more aggressive ignition timing.

Many ODB scanners can be used to monitor ignition timing on the fly. Its a simple matter to run one octane level and monitor the ignition timing, then run another octane level and monitor the ignition timing and see if there is any significant difference.

 

I can't understand why Ford would tune the motors to run on lower octane on these trucks, when they tune the Mustang with the 5.4 to run on premium.

As for programers/tuners, which is the best to get?

 

Mustang with the 5.4 is a blown high performance vehicle.

The trucks are just that... trucks. Most people don't want to make the extra 10-20rwhp and pay for the high gas. Besides that 87 octane is EVERYWHERE where as 91-93 isn't. Last year when the hurricane came through supreme and midgrade was EMPTY for over a month. Luckily I filled up my viper and truck tanks, plus a few 5 gallon cans with 93. I could just imagine the ***** storm if all the truck ran 93..

 

Larger heavier vehicles are generally tuned for lower octane fuel for better mpg and reliable power at the operating range the engine is intended to operate at.

They're trucks intended for utilitarian purposes, not lightweight high performance cars with high revving high compression engines.

Higher octane gasoline has its place but its not the brass ring to better performance in all applications. Unfortunately the common myths about octane and consumer level gasoline will continue to perpetuate and these type of discussions will never end.

 

What you have just described here is what a gasoline specification would define. Each company could have slightly different specs. When you go to a shell station you are buying gas that meets shell standards. You are correct in saying it could be made by any of the oil companies.

 

My rule of thumb

If your not pinging (pre-detonation) you don't need it.

Case in point my Civic SI calls for premium but I seen to be able to get away with alternating fill ups of mid and premium without any pinging.
My Wife's acura TL has some pinging under hard acceleration if I use mid so I alternate on that car too because she has a light foot anyway.

Our 2002 Stang GT called for standard octane but it started pinging after I did some performance mods to the engine and had to use premium to get rid of the ping.