Kinda backwards. It's realistically programmed for 91, with sensors and programming to pull timing when 87 is used. With an OAR of -1 (the lowest possible value), the engine isn't pulling timing. Anything from -0.99 to +1, timing is being pulled.

Where are you that has E20? Certainly none of it around here.

 

Widely available in the Atlanta area where I live. Currently in Ohio and have tested one pump so far (Sunoco) and it was E20.

 

I've never seen e20 in Ontario..most 87 is 10 percent. I only buy costco 91, premium gas and it is ethanol free. The 3.5 runs silky smooth and I can run it in my small engines (stihl) without problems.

 

Everywhere I have checked in the US Costco is 10%. Wonder why 0% in Ontario?

 

So using 87 octane I am not achieving 375 HP and 470 Foot lbs torque?

What are the numbers using the lower octane?

 

Check this website for your local area Pure-gas.org. Lists all stations with ethanol free gas in US and Canada. Ontario wide costco 91 is ethanol free, Canada wide Shell VPower 91, Canadian Tire 91, and Esso 91 for anyone interested. I can not numerically verify that improved fuel economy in the 3.5 TT running 91 will make sense financially, but you will be closer if its straight gas.

 

Yep, looking at that today. No pure gas anywhere near me. You are fortunate that Costco is ethanol free near you. Good top tier gas at a good price and no ethanol.

 

Seafoam has a lot of oil in it. Reduces the life of your O2 sensors.

 

Just going to point it out - "its been said" is not stating a fact.

Read Ford's literature for the F150. The only engine it states the advertised HP and TQ numbers are developed on on higher octane fuels is the 3.5 HO. Every other Ford engine in other applications clearly calls out when premium, non-minimum octane fuel was used to develop the power figures, just like only the HO engine is. (and it usually is 93 octane fuel, not just 91). They specifically did this so competitors cannot state "but that requires premium fuel" in the F150 lineup.

To date, I've never had a tank of 91 octane fuel deliver a -1 on the OAR. Nor did a few tanks of the one brand of 93 octane I've found around here. Under the idea that -1 is the max power the engine could produce, mine has never met the conditions to do so. It is always being retarded under the fuel available, and interestingly settles in right around 0 when running 87 octane (not +1).

Nobody will argue the ecoboosts don't take advantage of higher octane fuel. They do. Period. Whether the cost of doing so is worth it to you is a personal choice and nothing more. We can argue back and forth over what it was designed to run, but the reality is this: For best HP and TQ, premium. For lesser performance, but easier on the wallet, 87 octane will work just fine. End of story...

 

The new Expedition Platinums are rated using 93 octane and supposedly use an upgraded engine but no evidence to support this other than just using 93 octane on the same engine. The Platinum 93 octane rating is 400 Horsepower and 480 lbs of torque compared to the XLT's 87 octane rating of 375 horsepower and 470 lbs of torque.

I don't buy a 12% to 15% loss of power using 87 octane as that would make the standard F150 3.5L Ecoboost nearly as powerful as the H.O. 3.5L Ecoboost engine. Also Car and Driver has shown the F150 Limited with 87 octane only dropped 20 horsepower at the wheels (would be more at the flywheel). Flywheel horsepower would be about 25 horsepower. 25 Horsepower is only 5.5% of the F150 Limit's 450 horsepower with 93 octane. Still substantial but no 12%.

Our 2017 Fusion we have is rated at 231 Horsepower with 87 octane and 245 horsepower with 93 octane, a 5.7% horsepower loss with 87 octane. The earlier Fusions were rated with 231 horsepower with 87 octane and 240 horsepower with 93 octane, a 3.75% horsepower loss with 87 octane.