AND--use a Top tier gas, look up what stations are identified, they use More cleaners than the general crappy stations! I had to throw that in the mix lol-

 

I did run some 91 through mine, yes fuel mileage was better, but for the cost difference, didn't feel it was worth it. Even when towing my car trailer....didn't notice a difference.

 

My '15 XLT with 2.7 seems to get slightly better mpg with 93 octane. Now that it is cheap, why not?

Maybe 1.0 to 1.5 mpg better. From a steady 20 to 21.5 depending on how fast the trip is.

 

The ecoboost trucks are premium fuel suggested right from the factory for the best results with performance and mileage as mentioned in the owners manuals typically as well. Turbocharged engines need premium fuel to make a decent amount of power and MPG without struggling. It's been said they lose roughly 12-15% of Ford's advertised horsepower on the chassis dyno when using 87 octane since it sees a significant amount of knock and retards timing / boost under hard acceleration especially.

The stock figures for HP and torque are obtained on 91 plus octane premium fuels since that is what the engine was really intended to run factory. You can run 87 sure, but it's going to cause the engine to not make all the power and fuel efficiency Ford has designed these marvelous engines to provide. Tuned trucks it's even more important since they make about twice the amount of performance improvements on a 91 or 93 octane required tune when compared to an 87 tune which is mostly drivability and transmission improved type of ca since we cannot add a significant amount of engine performance through areas such as timing and boost without having the premium fuel needed to support these type of changes. So l always suggest stepping up to premium as does Ford when owner's are looking to get the best results possible from these direct injection turbocharged engines.

 

That is because the programming is done with a minimum octane of 91. The Ecoboost is design to run on 87, and programmed to run on 87, but has sensors to advance the timing as needed when higher octane fuel is used. Since Premium was down to $1.99 by me I filled up with it, and within a few miles of driving noticed the engine smoothed out and felt more aggressive. The manual suggests higher octane when towing or hauling, and for better performance, but does not require it for average driving. Ford knew what they were doing with the Ecoboosts, and kept it so that they can all run on regular grade fuel.

 

I know top tier has better additives, I wonder if running a can of Seafoam, or Lucas, or? a few times a year would help with the cleaning of the valves?

 

Definitely want to be cautious with adding your own fuel additives on these Turbo DI engines since they are a bit more sensitive than the traditional N/A Ford v6 power-plants from years back. The manuals usually tell you not to run any cleaners or octane boosters with threats of voiding warranty for certain stuff such as additives containing MMT / DDT, but those are more of an octane booster type of chemical. I've had a few friends that work as Ford dealer technicians that say Chevron Techron is one of the only additives they would suggest to E.B. customers, but I"m not sure which exact version. And I've read some horror stories on here and other places where additives caused them to begin smoking like a chimney from the exhaust. I always suggest to our customers to check in with their local dealer / service writer before running any additives just to be on the safe side.

 

Fuel treatments won't clean valves if motor is direct injected.
And how come Ford suggests top tier fuels in tier DI motors -what are they trying to clean besides the fuel line?

And where is the popcorn icon because we're in another octane thread and it's only Wednesday.

 

That is because European countries only have two octane grades 95 and 98. These ratings are a bit of a misnomer because the means to measure octane is different than in the USA. If the gasoline was graded using American methodology they would be 91 and 93 octane. European manufacturers build and tune to the gas available at home and the rest of the world has to bend to them. So ythey are tuning to the lower octane available.

 

What I don't get is that we have so many threads about octane and yet so few seem concerned about their motor being rated for max 15% ethanol (except 5.0 owners) when many pumps dispense E20.