SD_F1504x4

So does anyone who really knows engines well have a definitive answer as to what is healthier longterm for the flexfuel Coyote 5.0? Anyone have any good sources they can cite on some info? Because all I have seen is threads with the guys that refuse to use e85 on anything, talking like the guys that used to refuse to go fuel injected over carburated. Honestly, I want to take real good care of this truck since its pretty low mileage and I've seen plenty of F-series hit 200k with no issues (though I know I'll have to address the timing chain issue if it arrives but thats common in these Ford modular V8s). Has any one taken apart engines ran on e85 vs 87 and compared carbon deposits and such? I know economy is better with 87, but power is better on e85. And honestly, plenty of race engines are tuned for it and I've always attributed more power to a more efficient engine. And I don't want to run anything higher than 87, because that's what the manual calls for so that should be what the factory tune is for, and I rather avoid ping or detonation. Any info would be appreciated though.

gopherman

E85 gets you more power...but personally, quality tends to vary a bit more with E85. 87 works fine...but it's worth mentioning that the 5.0, being a higher compression motor does much better with higher octane (lower chance of detonation). I'd stick to E10 or less (if you can find it) with 87 if you don't want to put in premium. My main issue with E85 is that the adaptive fuel strategy is not perfect...so switching from E85 to E10 and vice versa can cause issues if you do it frequently and in small amounts (< 40% fills). I just stick with 93.

Catcher22

I have run nothing but E85 for 2 years and 62k miles on my coyote mustang and never had a problem and the engine runs much better on the corn then it does on 93..Im on my 4th tank of E85 in my coyote f150 and it's running great

SD_F1504x4

Damn, it's pretty much impossible to find ethanol free gas over here in California. Also haven't seen anything over 91 either. So how does it tune for anything over 87? I've had cars that recommend 87 or higher, but they have ping sensors to adjust for higher octane. What gas did they recommend for the Mustang Coyotes? And how different are the Mustang Coyotes in their fuel needs?

madmatt83

On the Toyota Tundra it calls for more frequent oil changes (every 2500 miles I believe) if you run e85 50% of the time or more, which I find interesting.

Fatdaddy

I have to run 91+ octane in my 19 F150 with 5.0.
Anything less and it knocks and pings something terrible...

N4HHE

The FFV 2.2L engine in 2001 GMC Sonoma said pretty much the same. Any use of E85 put the vehicle in "severe duty" category for double the frequency of oil changes, spark plug replacement, and fuel filter.

The explanation floating around at the time guessed that motor oils were not optimized for ethanol and ethanol combustion byproducts.

This is the same engine used in the Grumman LLV used by the post office for local delivery. Strongly suspect the Politically Correct Government uses nothing but E85 for postal deliveries.

oryanswoood

I've heard e85 isn't the best on motors but if you use an fuel additive with it it will prevent damage to motor over time. However I hear e85 has a higher freezing point than regular gasoline so in cold weather you probably won't want to use e85

Russell Shettle

Shell premium 93 is what I use exclusively.

bajaman

Well...considering that gasoline freezes at something like minus 100 degrees...one really doesn't have to worry about that!

Definitely a three year old thread resurrection that has been beat to death...the whole "what gas is better" question. There is simply no advantage to running high-ethanol content fuel unless you can get it for about $1.37 less per gallon than regular gasoline. Many have (and still WILL) argued that e85 has higher octane...up to 110 in some debates. That isn't exactly true...though often times the actual 'octane' of e85 can be around 90 octane. Regardless, there are countless studies that have shown how detrimental alcohol fuels are to engines.