Another E85 Question (2.7L)

[Steeroba]

Hi Everyone,

I believe I've read most of the other post on the E85, but I want to hear from 2.7L Bronco owners that made the change and use E85 exclusively. What if any modifications were made before making the switch to E85? What as been the decrease in MPG since changing? Any issues? How long have you been using E85? The price difference in California between E85 and 91 octane gas is over $3/gallon. Even with loss in fuel mileage, there is strong financial incentive to start using E85.

Yes- I understand it will void warranty.

Thanks!

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[Ducati1098]

Hi Everyone,

I believe I've read most of the other post on the E85, but I want to hear from 2.7L Bronco owners that made the change and use E85 exclusively. What if any modifications were made before making the switch to E85? What as been the decrease in MPG since changing? Any issues? How long have you been using E85? The price difference in California between E85 and 91 octane gas is over $3/gallon. Even with loss in fuel mileage, there is strong financial incentive to start using E85.

Yes- I understand it will void warranty.

Thanks!

Only modification you need is a custom tune.
Yes, E85 will decrease your MPG. Mine gets roughly 2 mpg less on E85 compared to 93, YMMV.
No issues at all for me, I’ve been running it most of the time for the last 2 years

 

[I_Fly]

I ran E85 on an Explorer without issue. Loss of milage, yes. Drop in overall HP, yes. Noticable for everyday driving, nope. Is it still drivable, yes. Issues beyond that. Nope! I would expect the same from a bronco. No tune is required. The ECU can handle that. So, try it. If the mileage and reduced power bother you, switch back.

 

[Brian_B]

No tune is required. The ECU can handle that.

You sure about that? Explorer was likely a Flex Fuel engine from the factory

 

[Ducati1098]

I ran E85 on an Explorer without issue. Loss of milage, yes. Drop in overall HP, yes. Noticable for everyday driving, nope. Is it still drivable, yes. Issues beyond that. Nope! I would expect the same from a bronco. No tune is required. The ECU can handle that. So, try it. If the mileage and reduced power bother you, switch back.

E85 doesn't reduce horsepower, it increases it if anything.
Also like mentioned by @Brian_B, if the vehicle is not flex fuel from the factory (like the Bronco is not), the PCM cannot handle it.

 

[Thatguylegit69]

And now we see why there was a drop in horsepower.
Not tuned or flex fuel = loss of power.
Thats my favorite line from some people "why run e85 when it'll male your engine run worse & rot your hoses in minutes!"

 

[BroncoChallenger]

And now we see why there was a drop in horsepower.
Not tuned or flex fuel = loss of power.
Thats my favorite line from some people "why run e85 when it'll male your engine run worse & rot your hoses in minutes!"

Yeah, the people who choose to remain ignorant are hilarious.

Modern fuel systems can handle the fuel - E85 won't degrade them. E85 CAN degrade older fuel systems that still have rubber lines.

The PCM is really the question - can the tune support E85 or not? The Bronco can't. If I recall, my wife's 2019 F150 COULD, despite being essentially the same motor but it's been a few years since we've had that truck so I can't recall (both 2.7 Ecoboosts). With an aftermarket tune, though, yes, the Bronco can.

 

[Ukko Wildtrak]

@Ducati1098 is the expert for sure, but adding my 2¢ on a possible alternative.

Not sure what the break-even point is for an e85 tune, but you can run e30 on stock tuning. Basically you can replace 25-33% of your fill up with e85. Some savings that way without the tuning spend up front potentially.

4 gallons of e85 mixed into 12 gallons of 93 gets you e29-e30 mix at 96 octane

6 gallons of e85 mixed into 12 gallons of 87 will get you 93 octane at an e35 blend.

https://morepowertuning.com/pages/e...qS9RgusU2s5CyzyDdcjgQ7ioNqA9U21cUNQ9mBtfEGP7u

Custom Tuned or not, just be aware that you are increasing the duty cycle of the fuel pump(s). If custom Tuned, I'm sure Five Star or your preferred tuner can tell you how much it will be raised and potentially how you can expect that to affect the life of the pump, if at all. AI math, but it makes sense just as a starting point for a comparison.

 

[I_Fly]

E85 doesn't reduce horsepower, it increases it if anything.
Also like mentioned by @Brian_B, if the vehicle is not flex fuel from the factory (like the Bronco is not), the PCM cannot handle it.

I stand corrected if the Bronco is not a flexfuel vehicle (like the explorer). My experience with E85 was not great so I don't give it much consideration.

 

[SCB FabWorx]

I've been running e85 off and on (mostly on) for the last 10,000+ miles. I have the ZFG tune for e85. I notice 2-3 less miles per gallon than 93 oct when I drive normally. But the power difference is significant when I don't drive normal, like a lot!

 

[SlowTrak]

ZFG/Lethal offers an auto tune version also. From what I gathered it's essentially a flex fuel tune. Only reason this is appealing is being able to pump any fuel I can find as opposed to driving around everywhere looking for an E85 pump. Not sure how popular E85 is anymore but I have seen more Shells carrying them but that is still not many pumps.

Downside is that you won't get the max hp you can dish out on the tune but at least you still get a bump in power.

 

[AZ4x4Adventure]

@Ducati1098 is the expert for sure, but adding my 2¢ on a possible alternative.

Not sure what the break-even point is for an e85 tune, but you can run e30 on stock tuning. Basically you can replace 25-33% of your fill up with e85. Some savings that way without the tuning spend up front potentially.

4 gallons of e85 mixed into 12 gallons of 93 gets you e29-e30 mix at 96 octane

6 gallons of e85 mixed into 12 gallons of 87 will get you 93 octane at an e35 blend.

https://morepowertuning.com/pages/e...qS9RgusU2s5CyzyDdcjgQ7ioNqA9U21cUNQ9mBtfEGP7u

Custom Tuned or not, just be aware that you are increasing the duty cycle of the fuel pump(s). If custom Tuned, I'm sure Five Star or your preferred tuner can tell you how much it will be raised and potentially how you can expect that to affect the life of the pump, if at all. AI math, but it makes sense just as a starting point for a comparison.

Is the Bronco fuel pump a PWM pump that increases and decreases flow volume? Figured pump pressure was fixed and the fuel pressure regulator would raise fuel pressure in the rails to match intake pressure but do they really flow more volume based on fuel grade? Would just expect the injector duty cycle to increase to allow enough volume at the standard fixed pump pressure.

so if the Bronco has a variable fuel volume pump, that could cause increased wear. Figured it was a fixed pressure pump with a pressure regulator at the engine to determine how much fuel psi goes to the injectors.

 

[Ukko Wildtrak]

Is the Bronco fuel pump a PWM pump that increases and decreases flow volume? Figured pump pressure was fixed and the fuel pressure regulator would raise fuel pressure in the rails to match intake pressure but do they really flow more volume based on fuel grade? Would just expect the injector duty cycle to increase to allow enough volume at the standard fixed pump pressure.

so if the Bronco has a variable fuel volume pump, that could cause increased wear. Figured it was a fixed pressure pump with a pressure regulator at the engine to determine how much fuel psi goes to the injectors.

It is PWM for sure to save on wear and tear. No need to run at 100% if the driver never gets on it. And you can run the inectors with a limited duty cycle as well. Saves wear on all fronts.

But are we talking the nTH degree here or something significant, I don't know honestly. In industrial pwm type motors, they are more efficient at the upper 25% of their range...I would think that would be true in this case too.

 

[swamp2]

4 gallons of e85 mixed into 12 gallons of 93 gets you e29-e30 mix at 96 octane

6 gallons of e85 mixed into 12 gallons of 87 will get you 93 octane at an e35 blend.

https://morepowertuning.com/pages/e...qS9RgusU2s5CyzyDdcjgQ7ioNqA9U21cUNQ9mBtfEGP7u

There is a lot to unpack and correct here...

Being frustrated by both the lack of availability and in many cases blatantly or obviously incorrect mixing tables/calculators, I did the detailed research and cracked the problem. Blending to a % ethanol goal is straightforward, however due to it being a non linear problem and with the complication of different ethanol levels in the base fuel and added fuels, blending to an octane goal is quite difficult, mathematically.

Specifically, your examples above can't be correct as they are incomplete. What ethanol level is in the base fuels? E85 is pretty well never 85% ethanol. The details absolutely matter.

In your first case, assuming 10% ethanol in the 93 and 78% in the E85 (a very common combo in the US) the volumes are close to correct, but resulting ethanol level isn't, it's actually 26%. You would also almost for sure want to take into account some tank reserve, which I've omitted so as to be as apples to apples as possible. The second blend you provided is significantly less accurate on both volumes and resulting ethanol!

Here is a screenshot from my Android App. More info on it at octanecalc.com .

 

[Ukko Wildtrak]

There is a lot to unpack and correct here...

Being frustrated by both the lack of availability and in many cases blatantly or obviously incorrect mixing tables/calculators, I did the detailed research and cracked the problem. Blending to a % ethanol goal is straightforward, however due to it being a non linear problem and with the complication of different ethanol levels in the base fuel and added fuels, blending to an octane goal is quite difficult, mathematically.

Specifically, your examples above can't be correct as they are incomplete. What ethanol level is in the base fuels? E85 is pretty well never 85% ethanol. The details absolutely matter.

In your first case, assuming 10% ethanol in the 93 and 78% in the E85 (a very common combo in the US) the volumes are close to correct, but resulting ethanol level isn't, it's actually 26%. You would also almost for sure want to take into account some tank reserve, which I've omitted so as to be as apples to apples as possible. The second blend you provided is significantly less accurate on both volumes and resulting ethanol!

Here is a screenshot from my Android App. More info on it at octanecalc.com .

I appreciate the correction on the math. And I'm downloading the app now actually. Point still stands that it can take quite a while to recoup the cost of the tune if overall cost savings is your goal. If you're just looking for an excuse to get a tune, well I think we'll support you here and say it will pay for itself! ...at some point

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