Just took delivery of a 2007 F-150 5.4 v-8. I just noticed this morning that its a Flex Fuel 5.4 which I didn't ask for. Is there any real difference in performance etc between the two engines when run of regular gas? The cost on the engines is the same but if I'm going to loose H.P. or reliability its going back! Thanks guys

 

The only thing I've heard is that your gas mileage will go down if you use E85.

 

There's a sensor in the fuel system that detects what you're running & retunes the engine accordingly. It should perform exactly the same as a non-flex truck if you're using the same gas.

And even if the MPG drops with the other fuel, you have to look at the COST of the fuel. MPG is a useful number, but what's more important is $PM (cost per mile). It wouldn't matter if you only got 10 MPG if you're only paying $1/gal because your $PM would be $0.10 compared to 15 MPG @ $3/gal = $0.20 for gas. Of course, I just made up those numbers for example - I have no idea what E85 costs or what MPG it produces.

 

Hmm... I wonder if I can convert my engine to FFV with using that sensor? It's a v6 though.

 

Not recommended. FFV engines have ethanol resistant 'plumbing', if you're running E85 on a non FFV engine you are courting disaster. Regular engines can safely run up to 10% ethanol blends I believe.

I'm not sure but I think E85 is about the same price if not a bit more than regular 87 Octane fuel.

 

Both versions of the 5.4L have the exact same spec's when it comes to HP and torque. To me, the Flex Fuel engines seem to be a tad more responsive. The Flex Fuel engine is a no cost option, and it probably adds a little to the resale value of the vehicle.

Locally, E85 is about $1 cheaper a gallon than regular 87 octane. There's a noticeable decline in horse power and mileage when using E85.

 

Per the new guidlines on MPG rating on vehicles, the 5.4 averages 14 combined with Gasoline and 10 MPG combined when using E85.

 

Thanks for the responses guys. I really like this truck and didn't want to have to return it and wait for another to be built. I'll only be running gas as thats the only thing available in my area anyways

 

E85 is probably just another fad, like it was in the 70's during the gas crunch. Ethanol fuel is priced so you really save nothing. Okay, you save $15 at the gas station because E85 is a bit cheaper. However, E85 also contains a lot less stored energy than gasoline, so the motor has to burn more of it to get performance that still doesn't equal gas. So you're back at the fillup station a lot sooner. You save on the fuel, but have to buy more of it, so you really save squat. Some places E85 is no cheaper than gas at all.

Running regular pump gas in a FFV motor should have equal performance to a non-FFV motor.

 

I purposly got mine with the FFV system (inaccurate to call it a FFV engine. Engine is the same.. calibration and fuel system components are diff) because of the premium components in the fuel system. Also because if the stupid E85 catches on I won't be stuck paying more for regular fuel. At least Fords FFV is a no cost option. I guess dudge it costs $1200 more to get the FFV system.

 

My 5.4 came with the FFV option and I was happy.

First of all, I'll probably never use the stuff as long as I have the option...but it's nice to know that if, in the future, E85 becomes some big thing that is available everywhere (like if 10 of the 12 pumps at the gas station have E85 and only 2 have regular gasoline), I'll be ok with that.

I figure it couldn't hurt to have the option.

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Also, the FFV vehicles come with a sensor and also they come with complete stainless steel fuel lines whereas the non-FFV vehicles don't.

 

I have an 06 F150 screw with the 4.6, I know that the 5.4 07 can use e85 and that the 4.6 engine in certain fords can but I dont see that the 06 f150 4.6 can. If the engine can, and the truck can, maybe I should try?? Any info?