Originally Posted by Rick boomer

The Duratec 3.5L has a 10.3:1 compression ration which puts it solidly in the 91 and above octane regime. To run on regular it must be detuned.

Gasoline motors with basic underlying designs that run on regular fuel see no improved performance on premium, no increased power or torque.

Start with a false premiss and you can get a false conclusion.

Yes, in the "old days" many engines designed for regular might have benefitted with premium but that was because premium fuels had better detergency than regular fuels in those old days. It had nothing to do with octane. Now, regular fuels must have equal detergency.

http://www.daytona-sensors.com/tech_tuning.html

Originally Posted by Rick boomer

No one ever said that the engine didn't have the adaptive ability to run on any gasoline fuel from 87-93. That said, the simple fact that many people have had trouble running on 87 says that the adaptive technology does not work for all ecoBoost motors under all conditions, these adaptions are many and complex, all these adaptions reduce power and torque.

The statement was that the basic underlying design was that of a premium fuel engine and it is. That the basic underlying design would require premium fuel and it does. That maximum performance would be using premium fuel, and Ford agrees. All true.

Conclusion, it is understandable that some people have trouble with regular fuel. It is understandable that maximum performance is with premium fuel. It is understandable that adaptive technology is required to run with regular fuel. It is understandable that the adaptivre technology does not always work on all ecoBoost motors under all circumstances for all people. No two of these motors are exactly the same. They are mass produced and have variable behavior. Not all will function optimally. Almost all will function to their individual optimums on premium fuel (according to Ford).

That does in no way mean what you argue against, that premium fuel is required or even suggested. No one is ever required to run premium fuel. If you are running on regular and having trouble a fix might be available by upping the octane and it is easy to understand why that fix would work. If you are in need of optimum performance do to rigirous load or towing requirements, you might do better with premium fuel and that would be understandable. If you are not having problems and do not need optimum performance you will probably operate more economically with regular fuel. If you want to drag race, you might do better with premium fuel, and would be easy to understand.

If you have trouble understanding breaking down the understanding of different componets and functions of modern motors into their underlying basic components and the physics, chemistry, and engineering of those components what can I say. If you can only understand the net overall integrated behavior then you will not be able to understand how the system functions, fails to function, or it's optimum performance conditions.

Originally Posted by packplantpath

Find some posts from these"many people" claiming issues running 87 octane. Never seen that one. Never. Not once have I seen a post reporting that.

Originally Posted by MadocHandyman

If I remember correctly, he even claimed there were lawsuits against Ford regarding this supposed octane issue.

Originally Posted by packplantpath

I won't say they don't exist. But I've been around a while and that one has never come up in the "I almost got killed passing a semi"threads.

I'd like some links!

Originally Posted by scap99

I almost got killed passing a semi, yesterday.
Only because the tundra I got in front of almost plowed me when I had to slam on my brakes to keep the guy that was in front of me from sideswiping my truck because he thought he could pass without looking over his shoulder...

Originally Posted by Al Kohalic

Ouch! Glad that nothing happened to you on that one.

Originally Posted by TwinTurboFx4

I put regular in mine but about 5 hours ago on my way to michigan from kansas city I applied some throttle to pass a semi all of a sudden my truck started to shutter and check engine light was flashing so I pulled off to the side of the road, shut my truck off, and restarted it. Ran fine the rest of the way 280 miles. So I'm thinking it was a miss fire so when I got to michigan I put 93 in to see if it will make a difference. Other than that im taking it to the dealer Monday.

Originally Posted by benson_chris

Spark plugs. My truck did this. Check plugs. Gapped double what they should be. Bought new plugs, gapped properly-no problems since