In as simple terms as possable,whats difference between flex fuel and reg engine,and how do i know which i have?2000,3.0 xlt.auto trans.Thanks.Paul

 

Flexible fuel vehicles (FFVs) are designed to run on gasoline or a blend of up to 85% ethanol (E85). Except for a few engine and fuel system modifications, they are identical to gasoline-only models.

 

The difference is mostly in the electronics. The pcm on a flex fuel has the ability to detect ethanol content via sensors and adjust fuel mixtures to the correct mixture of air and fuel flow so that the engine runs correctly. The thing to remember is E85 only has about 3/4 the BTU value that pure gas does. And the engine parameters have to be adjusted to allow for the difference. As a result when running on E85 the gas mileage does suffer. A recent test on a flex fuel truck we had showed 18 Mpg on regular unleaded and 12 on E85. I have used salvage engines that where flex fuel and put the standard electronic parts for a non flex engine on and had no issues. I believe the internal parts are the same, though I cannot prove that.

 

u would have a green leaf on ur tailgate if its flex

Matt

 

with that sentence you just hit on exactly why you are losing economy when running E85. To make ethanol viable you NEED to have a totally different engine to utilize the properties that ;make it different. whats funny is if people were to go out and by 110 sonoco race gas they would see a similar although not quit as drastic reduction in economy. Ethanol is 105 octane and would work just fine in a vehicle with 11:1+ compression and at that range with a proper PCM setup you might actually see an increase in mileage but would definatly see an increase in power.

 

Ummh, Monster, yes the octane is there, but the BTU is not. Octane is actually a measurement of ability to avoid compression ignition, and to burn without exploding. High octane fuel has no more energy in it, but will not self-ignite nor propagate an explosive type of burn. You should be able to bump the compression on the flex, and then get more hp/torque, but wouldn't the fewer BTU still make it use more fuel? Remember, diesels have 18:1 (high, any way) AND they have more BTUs in a gallon of diesel, so they get more mpg. I don't think E85 or even E100 would get mileage no matter what you do to the engine.
I believe E100 is equivalent to what they were running in Indy cars, and I remember back when there was a wreck where several gasoline burning cars were demolished. They outlawed gasoline because the fires were hotter, and went to ethanol/methanol because it burned cooler. (Problem was, we are not able to see an alcohol fire... )
You could also burn propane, which has high octane, in a high compression engine, but it still would not get the mpg equivalent, because of BTU content.
Maybe I'm nuts... at least I'm ignorant to make up for it...
tom

 

Tomw I think you nailed it. There is no way you can ever get the same milage with e85 that you can with gasoline. I believe it takes about 20% more fuel with the ethanol blend. You can however extract more power from your engine by bumping the compression. I have heard that you can bump it up to about 12:1 on 105 octane E85. I'm not sure how much our stock bottom end would like the extra squeeze thpough. Oh and Indy cars still use 3% gasoline in their fuel. It is not a performance thing, they do it to keep the crew members from drinking the fuel.

 

The problem is too many people have gotten to hung up on BTU ratings which has been pushed by the oil companies to keep any competition looking bad. But think about it if you have more power due to things like higher compression then you don't have to work the engine as hard, or you can run a smaller engine and get the same power level thus reducing the fuel requirements to do the same work.
I can prove BTUs do NOT tell the whole story with my diesel.Both #1 diesel, and biodiesel have less BTU then #2 diesel, now when we blend #1 for winter use my fuel economy drops at least 10%, but when I blend Bio diesel into straight #2 well if BTUs where the whole story I would see a similar drop in economy but just he opposite happens my economy raises approx 5-10%. The oil companies want you to believe that the BTU content is the entire answer all the time, well if they can convince you of that they win all the time because yes it's true there isn't much out there that has more BTU's then petroleum products.
Now I don't think Bio fuels like ethanol, or bio diesel are the entire answer not in any shape or form. There is no magic pill to get us off gasoline IMHO. But refusing to look at it because of something as stupid as "it has less BTU's" is giving up and frankly I don't give up easy. It's like this if ethanol can reduce 2%, Bio diesel cut another couple percent, hydrogen cars maybe reduce 3%, pure electrics say 1%, and you keep going with more and more small reductions then pretty soon your starting to make an impact but if you look at every choice and say well it's gong to be less efficient because BTU reduction so not going to use it, pretty soon we are at double current levels, the oil industry has even more of a strangle hold on the rest of us and we are 10 yrs down the road without any new technology cause nothing looked like the magic pill and then still have to do the research.

 

I agree with monster baby, you will not get back to even on ethanol by raising the compression but you will get close due to less work required of the engine. I have a custom Diablo chip in my 99 RAnger supercab with the 2.5L four. currently my MPG is 4-5 less than gas but my power is up and the price spread of $.72 per gallon more than makes up for it.

Example:87 octane gas $2.67 gal. 250 miles at 22MPG= $30.34
105 octane E85$1.95 gal. 250 miles at 17MPG =$28.67
at this price spread I can drop 5.932 MPG and still break even.

I now have a truck that if I wanted to could get a fuel permit and make my own fuel to say scr** you oil companies, I don't need you..

 

A FFV Ranger 3.0L has a "V" as the 8th digit in the VIN.

A regular-gasoline 3.0L Ranger has a "U" as the 8th digit in the VIN.

As noted above, the base engines themselves are the same. The differences lie essentially in the fuel-delivery systems and the PCM logic. By "fuel-delivery system" I am talking about the FFV's different fuel injectors, fuel pump, fuel lines, fuel filter assembly and the flex-fuel sensor which tells the PCM how much alcohol content is in the fuel.

See: http://www.babcox.com/editorial/us/us020628.htm