Maximizing MPGs at high speed

[Ziggy73]

So I recognize that driving fast is counter to getting the best MPG, so I’m just trying to figure out what settings I can change to maximize for my situation.

I drive mostly highway miles where the speed limit is 75-85mph so I’m usually driving 90 just to not get run over.

I usually run 87octane in Eco mode and get about 18MPG.

Thoughts on locking out gears, ECU tune or changing rear diff gearing?

Bed cover, possibly folding in your side mirrors on long stretches. I've heard a few say that higher octane helps. I'm in a Facebook group where a administrator is thinking about working on a full belly pan, that helps quite a bit. Make sure your front air dam is functioning properly, that helps as well. Keep tires inflated to around 40 psi.

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[HammaMan]

So here is some admittedly non-scientific data from my Dallas-Austin-Dallas trip last week.

Dallas->Austin
had a half tank of 87e10, drove without CC, attempted to keep RPMs right at 2k. Of course sometimes more sometimes less but the goal to was keep it steady.
2kRPMs = 80mph and 19.7mpg for the trip.

That's pretty much what I get.

As for your e85 mix, if you're putting in that much e85, you really don't need to bother with the premium fuel as you're already providing the higher octane equivalent. That's why there is but e85.

 

[nitrobass24]

That's pretty much what I get.

As for your e85 mix, if you're putting in that much e85, you really don't need to bother with the premium fuel as you're already providing the higher octane equivalent. That's why there is but e85.

Yea I was aiming for close to an E20 blend as that seems to be the max the engine can handle without a separate tune. My assumptions were that the e85 would measure around 65% Ethanol based on previous experience.

I suppose your point is that I could have run more e85 + 87e10 to achieve the same effect.

@Snakebitten I recall you doing something similar for another thread...what's your thoughts here?

 

[HammaMan]

Yea I was aiming for close to an E20 blend as that seems to be the max the engine can handle without a separate tune. My assumptions were that the e85 would measure around 65% Ethanol based on previous experience.

I suppose your point is that I could have run more e85 + 87e10 to achieve the same effect.

@Snakebitten I recall you doing something similar for another thread...what's your thoughts here?

I haven't come across the exact point where the high pressure rail can't flow any more fuel, so if you're not going full WOT, you should run into an issue playing. If you're blasting around in 4a shooting for really poor mileage that's something else entirely. I'm surprised we haven't seen any shop doing more with the port injectors as it should be the easiest means for allowing higher ethanol levels.

Without a tune specific for the fuel blend you're running, that you've verified the ethanol content that is, once you get to or above the octane detection limit for the sensor, you're just burning $. There's a few variables at play, particularly what the e85's actual ethanol content is (assume nothing). However, as you've mixed it, but with 87, you should be making the truck happy. Only those who chase the bleeding edge should be concerned with matching their tune (what fun that is, eh) with actual ethanol content of the fuel.

 

[Snakebitten]

Yea I was aiming for close to an E20 blend as that seems to be the max the engine can handle without a separate tune. My assumptions were that the e85 would measure around 65% Ethanol based on previous experience.

I suppose your point is that I could have run more e85 + 87e10 to achieve the same effect.

@Snakebitten I recall you doing something similar for another thread...what's your thoughts here?

My local E85 pump tested at ~60%(?) if I recall.
I mix about 4 gallons in with 26 gallons of E10. (Powerboost has 30 gallon tank) I did the math at the time and it left me with a comfortable cushion under E20. Like you, I don't want to tax the oem calibration beyond E20

My main purpose for doing so is my fanaticism with KR/OAR/Timing on the ICE. The PIDs clearly indicate that there is harmony in the combustion chamber and the truck is happy. And since the Powerboost still gets me north of 650 miles a tank, I don't think I'm giving up enough fuel economy to spoil the party.

I absolutely love the torque management software Ford has on the Ecoboost. I've owned a few of them over the years and they have dialed it in nicely for an oem calibration. Truck is amazing!

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