I’ve heard somewhere that these trucks (3.5 EB) love premium and that they make more power.

What is the minimum requires octane? How many people use premium over 89 or 87octane?

 

I use the minimum that it is designed to run which is 87.

You can go premium if you'd like. Preferred if you are towing a heavy trailer. The book says "for max performance" or something like that, however i don't drive it like a race car, therefor I have no need to waste the cash.
When I put Premium (91 in California), for my normal driving I see zero gains in any part of the term. Rungs just as good and gets the same MPG on 87. If I spent more dollars on Premium, which for me is only 30-cents a gallon, I actually lose money as any MPG gains don't allow me to travel far enough to make the cost of premium a winner.


And thanks for this, it's been about 10 days since the last "what gas" thread was posted We were running out of snappy humor threads until now.

Note: The minimum required is in the owners manual, or maybe at the fuel door too.

 

They for sure make more power on 93 than they do on 87 or 89 although they run fine on 87 and 89!!

 

It's a turbocharged vehicle...for best performance...you run premium although you can run **** gas in it. The ECU is obviously programmed to learn and adjust the maps accordingly so you are fine.

 

Try a few tanks of each and see for yourself----Just make sure you run TOP Tier gas all the time!!! BUT for me and a HO turbo engine it only gets Premium gas period!!!! the extra 10-15 bucks a tank is oh well--who cares!!!

TOP TIER GAS

 

Running the 3.5 why do you need more power? Unless you are towing heavy or up in the mountains you’ll never use the full power band. 87 is fine.

 

I ran 87 octane in 2015 3.5L EB. It ran fine. I sometimes ran 88 octane (up to 15% ethanol) and it still ran fine (slight drop off in mpg's though.) I haven't filled up my current truck yet. Will do so today with 87 octane.

 

I ran 87 in my 16 most of the time. If I knew I was going to tow something I would switch to 93. My 20 Expedition I run 87 all the time, when you need to work it use 93, for normal running 87 is fine.

 

93 because you can never have enough powah!!!

 

The manual recommends 91 octane for best performance and towing.

The most important thing to understand is, these engines can run 87 octane because of computer controlled direct injection and ignition timing. And that applies even to my 3.3L. If it werent for that, theres no way I could run 87 octane in a 12:1 compression motor.
However, there is only so much direct injection and ignition timing can do. So if you have an Ecoboost and are working the engine hard and towing heavy, it has a very good possibility of getting hot running anything under 91 octane.
The 5.0 and 3.3 have a bit more "give" in that area as even though they are high compression motors, they are not boosted.
You dont hear about 5.0 overheating, you do hear about the 3.5 Ecoboost overheating and some of those dudes are running 85 octane towing and wondering why!
Ecoboost cylinder pressures are higher, especially under high load and high boost situations.
Daily driving: 87 octane
Ecoboost during a long, hot and strenuous tow: 91 octane.