What's the best fuel for a 3.5 EB? Not so much for performance, but best for engine life, fuel injection, turbo life etc...
High octane? Ethanol fuel or non ethanol?

 

Mines doing fine on 87! That’s all she’s ever had, and that’s all she’ll ever get!!

 

The main differences is the fuel octane and type. While the octane on regular gas will make the engine adapt to performance, a lower octane will leave more deposits over time. Ethanol will clean the engine better but also removes oil film more than regular gasoline so it can wear out parts slightly quicker. Best fuel for longevity will be 91/93 (or at least in my opinion).

 

I run with mid grade, top tier fuel. I think more frequent oil changes than the oil meter recommends is a better approach. I do mine at 4.5-5 k miles.

 

I run 87 Shell and change my oil at approx 7500 miles. I'm not brand loyal on oil, but do stick with 5W30.

 

Unless low enough to cause damage, octane has nothing to do with engine life. What your SHOULD concern yourself with though is the additive package. Easiest no brainer way to always get a great additive package is to buy top tier gas.
EDIT: Funny thing locally. Walmarts have top tier gas and the Sam's clubs do not. Same gas, different additives.

 

Unless you can look at live data, it is subjective. Seat of the pants dyno doesn't count. Knock retard does. It is also dependent on the driving habits of the operator and the power needs for the work performed.

Lower octane causes the engine control module to pull timing to prevent knock. Higher octane will allow the ECM to add timing or advance the timing. This will give you more power. What correlation that has to timing chain issues or longevity is open for debate. I would prefer to keep the ECM in mid point or higher, that way if I get a bad tank I should still be above 87.

 

The higher the ethanol content, the more the trend points to increased wear. Ethanol combustion gases are more harsh and break down oil more quickly than those of regular gasoline. The higher the content also the more rich the mixture needs to be which leads to increased wall wash. In theory anyways. Real world, any wear difference won't stand out in any measureable/noticeable amount

 

Go by what Ford recommends in the manual which is: Top Tier fuel, 91 octane or higher for overall best performance. Ethanol, by the way, does not burn as hot as gasoline and has the equivalent of 100+ octane. The other half to the longevity equation is with keeping the oil full, clean and changed.

 

This is true in an equal volume situation. A lot of people don’t realize though that with the higher AFR required due to the reduced thermal energy of ethanol, that in a power producing setting your EGTs will actually be a fair bit higher with ethanol vs gasoline.