I know you cannot use E85 but up here in northern Minnesota most 87 and 89 octane contain up to 10% ethanol. From my reading Ford says you don't have to use premium but is the 10% ethanol harmful to this motor??

 

E10 fuel is fine for use in the EcoBoost. The manual states that it's the max allowable ethanol mixture allowed though.
JL

 

Is there any advantage to using midgrade fuel? Around here, regular and midgrade are normally the same price.

 

double post

 

The same price?...how can that be? A few octane more is not really going to do anything for you and I doubt you will notice any difference. The mid grade fuel is basically there in case you are experiencing knocking in your motor at the lowest grade fuel. If you are not experiencing any knocking then the mid grade fuel will only help extract more money out of your wallet.

 

The engine is designed to run optimally on 87 octane 10% ethanol fuel.

 

I've used the gas with both 10% ethanol and no-ethanol fuel, regular, mid-grade and premium. I've noticed a cleaner exhaust pipe (no soot build-up) with the ethanol-free gasoline. I don't know if that's good or not??

 

I get around 1-2 mpg better with non-ethanol gas.

 

I use 87 most of the time. I have run premium a few times and it seems to add 1 or 2 MPG but not enough to warrant its use for the price difference. I to have came accross a couple stations here in MN that offer the 89 octane for the same price. I always put it in when that is the case in all my vehicles. Though I don't know if I gain anything. Ethonal does us no favors for power or Fuel Efficiency. I use Oxy free fuel in all of my small engines and boat. Too bad is wasn't legal in my EcoBoost cause I would use it in there as well.

 

Seems like that is common for most vehicles......all part of the ethanol rip-off that we're not supposed to know!

 

Maybe so ! I have been driving modded diesels for the last 11 yrs.