3rd Gen Ram Tech2002-2008 Rams: This section is for TECHNICAL discussions only, that involve the 2002 through 2008 Rams Rams. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
Do not run E85 in a vehicle not designated as being able to run E85. Ethanol is a very corrosive alcohol and in that heavy a dosage will eat up all kinds of things on you.
Besides, 99% of people with E85 vehicles run E10 anyway, it's cheaper yes, but fuel economy is so poor with E85 that it's actually cheaper to run E10 (or especially ethanol free gas).
Even our beloved government which doesn't always tell us the 100% truth, acknowledges a 25% fuel economy loss when running E85. Real numbers are often more like 33-40%...
The flex fuel vehicles have a special fuel sensor that tells the computer what mixture of fuel is flowing to the injectors so the mapping tables can be shifted. E-85 does need to be enriched between 23% & 27%. E-85 really isn't E-85 all the time. During the cool winter months it is E-70.
I beleive that you will not be able to convert your non-flex fuel system to a flex fuel system easily or cheaply. It would be better to just find one of the factory built versions to play with this option.
I have a friend who has a Ford 1/2 ton truck with this option and rode around with him yesterday and couldn't tell the difference in performance. The difference was he paid 3.25 per gal for the E-85 instead of 3.79 per gal for 87 octane fuel. This had a savings of 54 cents but it really wasn't a savings at all. He was claiming that his fuel mileage only dropped 2 to 3 mpg. 17 mpg to 14 mpg is about a 18% reduction. That means the cost of the fuel would have to be 3.11 per gal to break even. Normal fuel enrichment should be at lest 23% but the computer can add a bit of ignition advance so the milage hit was 18% instad of 23%.
The amount of energy used to create E-85 vs. the amount of energy we get burning it just doesn't make sense. If we look at the cost of 91 octane fuel it starts to make more sense. If we look at E-85 compaired to Race fuel the math now starts to make more sense. We can run 14.5:1 compression and make some great power at less money than racing fuel.
Here in Phoenix it is still hard to find gas stations with E-85. You have to know were all the stations are and plan things better if you really want to use it.
The Pimentel study counted the energy required in every step along the process to make ethanol. transport, seeding, growing (I don't know the last time any of you had to pay for the energy of the sun while plants are growing...), irrigation, reaping, etc. While his comparison did not count to the same detail all of the steps required for other energy types. If you counted what is required for other types of energy to that detail there was no other form of energy that passed his criteria, either.
The flex fuel vehicles have a special fuel sensor that tells the computer what mixture of fuel is flowing to the injectors so the mapping tables can be shifted.
Are you sure? The very first flex fuel vehicles (FFV) from Ford in the late 70s, early 80s that were done for the State of California had optical fuel type sensors, but all more modern FFV use the O2 sensor to regulate fuel flow. Though, I think you have to have larger injectors when you run alcohol (not completely sure about that) I am not certain you have to have a sensor to determine fuel type.
Inside your fuel door should be a sticker, it tells you if you can run E85 or not. There's a whole section in your owners manual that tells you about using E85 and what to do if you do. If you dont have an owners manual go to the RAM website, you can still download one for a 2004 for free!
If you have your window sticker or build sheet check the sales code for your engine, Both 4.7's for 2004 are "Magnum" engines. Sale code EVA is the gas only engine, EVD is the flex fuel/E85 compatible engine.
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Last edited by Fleet Guy; 03-08-2012 at 09:56 AM..