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Vincent, Ford Senior Master Technician
Category: Ford
Satisfied Customers: 1450
Experience:  28 years as Tech.
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2007 Ford F150: with the ffv 5.4 ltr engine..highway

Customer Question

I own a 2007 Ford F150 with the FFV 5.4 ltr engine. In burning ethanol, I get only 11 mpg on the highway. Burning regular gas I get 18 mpg. Is there a computer chip that will allow me to get better mileage with ethanol without voiding the warranty?
Submitted: 9 years ago.
Category: Ford
Expert:  Vincent replied 9 years ago.

The problem is not the programming of the computer, the problem is that ethanol does not have as much energy (BTU's) per pound (or gallon) as gasoline. The engine is already optimized for what fuels you are running.

Keep in mind that if you run the engine any leaner (which you cannot as the fuel calculations are checked using the oxygen sensors in the exhaust system) or advance the spark further (which you cannot, as the spark is set using knock sensors) you run the risk of melting pistons or other damage.

Vincent and 2 other Ford Specialists are ready to help you
Expert:  Vincent replied 9 years ago.

Here, I pulled out an old Bosch book of mine and looked up some numbers for you. This will give you an idea of the differences.

These numbers are BTU's Per U.S. Gal.

Gasoline: 125,000 btu's

Ethanol: 84,600 btu's

Methanol: 64,600 btu's

Gasohol: 120,900 btu's (10% Ethanol, 90% Gasoline)

Diesel: 138,700 btu's

And now you also understand why diesels get better fuel economy. Also that is for 91 octane gasoline. Lower octane (87 and 89) actually have more btu's per gallon.

Customer: replied 9 years ago.
Reply to Vincent's Post: Vincent,
Thank you for the quick reply, although I already knew the answers you so kindly provided. During a recent trip while fueling with ethanol I spoke with a gentleman filing up his 2007 Silverado with an FFV engine. He stated that he had changed computer chip when I found out that he was getting 11 mpg vice 18 mpg. Although a GM product, the BTU info that you just provided applies equally to his vehicle as it does to mine. Either he was not being honest about it or he knew something we both don't. Care to comment?
Expert:  Vincent replied 9 years ago.

Sure, he either slowed down his driving or he was not being fully honest. Most computer chips will only modify things like timing and fuel flow so much. And most of them really only work at wide open throttle settings. Here is the problems. The computer looks at Mass Air Flow sensor voltage to determine the amount of air going into the engine. With that information, the computer calculated fuel flow. When the burn occurs, the spent exhaust gasses leave the combustion chamber and flow past the oxygen sensors. Those sensors send information to the computer as to how much or how little unburnt fuel is in the exhaust system. The computer uses that to modify its fuel calculations. Kind of like doing a math problem backwards to check the answer. We call that closed loop.

At part throttle operation, the computer is doing that comparison constantly. Any modifications to the fuel look up tables will be compensated for by the O2 sensor outputs. Where that changes is when you are operating at wide open throttle (max power) When the computer sees greater the 90% throttle, the o2 sensors are no longer part of the calculation and any programming will have an effect.

When chip designers are changing the parameters of the computer operation, their biggest concern (and target market) is the performance crowd. Hense, what they are able to do is generate greater horsepower, without having a detremental effect on fuel economy.

With spark cuves, you hae the same problems, especially with engines (like yours) that hae knock sensors. Again the timing is advanced until the spark knock is heard by the senosr and then it is reduced slightly. On a modern engine, the timing correction can happen from one firing event to the next. And at 3000 rpm that means within .04 seconds (if my math is correct). Again there is not much that the programmer of a chip can do to change that. Keep in mind that this is all occuring during part throttle operation.

There is just only so much that can be done with a fuel that has 67% of the energy of 91 octane gasoline.

And by the way, that is about what you are getting (61%)

Customer: replied 9 years ago.

I understand. Thank you very much. I guess I'll have to wait until Ford brings out a V6 bio-diesel. I think the American public is being sold a "bill of goods" with these flex fuel engines, although they "can" break the countries dependency on foreign oil and keep a lot of Midwest farmers doing pretty well. Sure wish they would put in a "few" more E85 pumping stations here in California! Outside of California, on my way to my South Dakota home, I can get all the E85 I want, and at about 80 cents to $1.50 cheaper per gallon than gas, which makes it worth while, economically anyway. By the way, I tried that "slow down" driving you mentioned about the individual I met at the station, and it does not make much of a difference in my truck. At 72 mph I get 11.3 mpg on ethanol. At 78 mph I get 11.2 mpg.
Expert:  Vincent replied 9 years ago.

Oh don't get me started. If you live in Cal then you are already are getting the shaft. Lets look at oxygenated fuel. The cost is greater, as the processing is more expensive, the energy btu's are lower, and to reallly add insult to injury, it makes the engine run richer and therefore burns more fuel.

Go back to the example about the O2 sensors. If you are running oxygenated fuel, you have more oxygen in the fuel and therefore more oxygen in the exhaust gasses. The computer sees that as having a lean mixture and adds more fuel to compensate for the issue. Ethanol does the same thing as well as there is a consideble amount of oxygen in ethanol.

And yes we are being sold a bill of goods with ethanol and methanol. It is all part of the government's requirement to quote - unquote our dependance on global fuels (see liberals). But with the increased amount of farm land being devoted to fuel plants, the great cost in fuel to grow and harvest those crops, etc, we are seeing an increase in the cost of food as well as fuel.

Until there is a demand for bio diesel, we won't see it. You notice that most of the small diesels are European (VW has an excellent diesel) that is because the Europeans have been dealing with the fuel costs for much longer then we have.

Take a look at this data for world fuel costs:


Customer: replied 9 years ago.

Very well said and I totally agree, except for the rising cost of food. From what I've read (ironically there are two ethanol plants producing well over 1 million gallons of corn based ethanol about aXXXXXfrom my folks place in Fresno, CA, which they ship out of the state) it's not the food and or fertilizer portions of corn processing that gets used in ethanol, so that has nothing to do with the food issue. If the truth be told, which never comes from the government and or the lobbiests, such as the farmers and ethanol producers, the rising cost of food is based solely on the rising cost of fuel, be that diesel,gas and or ethanol. Everyone has to get their cut. I'm sure as a master technician for Ford, you can see what happens when your suppliers raise the price of parts etc, etc. And what is all this based on? The good old American dream of capitalism. As for being a Californian, well, yup, I agree. California is the land of the fruits and nuts. But please do not count me in with that crowd. I've lived in and out of Asia for the last 40 years! The current California is definitely NOT the state I was born and raised in! Are you kidding? Arnold "The Terminator" as Governor? Thanks again for all of your helpful information. And by the way, I do love my Ford F150 truck. It was a gift to myself for surviving 40 years as a Navy fighter pilot, three of those years in Vietnam. $5 gas prices? It's coming, but quite frankly, I don't care one way or the other! The "Welcome Home" I got in 1972 and those three years in country......... well sir, I've paid my dues! Thanks again. I've enjoyed "speaking" with you!
Expert:  Vincent replied 9 years ago.

Well done and thank you for your service. Just so that you know, we have probably shared some of the same ground. My father was a career man with the Navy. Joined when he was 15 and saw his first combat before he reached 16 during the Pacific Theater. I was born at Pax River NAS in Maryland, and we had lived, until his retirement, pretty much everywhere. That includes 3 years in Japan while dad was flying missions over SouthEast Asia. (Flight Engineer)

The only thank you that I was able to give my father, was internment in Arlington. And this is not the country that it should be. We need another Ronald Reagan. Although G.W. I think will go down in history as a far better President then anyone has given him credit for.

Fruits and nuts indeed!

As for the F series, it is amazing just how far trucks have come. I can remember when they didn't come with A/C and Power Steering. Now they are just as comfortable and quite as a Lincoln.

Cheers XXXXX XXXXX Navy!

Customer: replied 9 years ago.

Thank you very much.

I flew out of Pax River myself a couple of times. Lived in Mt. Vernon, VA.

Sorry to hear that you had to wait so long to say thanks to your Dad. That had to be a real bummer.

Yes, my F150 Super Cab is all tricked out and rides like a dream. Even got the leather interior. Got myself a Leer Topper for the 6.5 foot bed. I think the only thing missing from the "build sheet" was the Sirius radio. My Dad had one of the original Ford F100's. While he was still teaching collage he and a couple of friends at school converted the engine to propane. Ran like a top. Again, the only problem was that most of the time propane was more expensive than gas, if you can believe that.

Fly Navy! My primary aircraft was the Navy's Phabulous F-4 Phantom II. Served on seven different carriers. Am just happy to be alive! That's another reason I really don't care how much gas costs me. We use to dump about 200 gallons every mission just to get down to carrier landing weight.

All the best, XXXXX XXXXX again!

Expert:  Vincent replied 9 years ago.

Ah the good old days.

When we were stationed at Magu, Phantom pilots used to fly over our house and bust our windows. (my dad was not a very popular Chief) I still love that bird and I remember when the Angels Flew her.

I remember the guys being able to bust Mach during air shows, Live Fire Demos, etc.

Phantoms Phorever! indeed.

However, "No Kill Like A Gun Kill" is still my fav (The last of the Gunfighters, F8 Crusader) sorry, I just had to do it.