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E85 conversion for economy

Old 07-28-2010, 01:25 PM
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E85 conversion for economy

Can a completely stock EJ series be tuned to run E85 just simply from an economical stand point. Not looking for gobs of power just reliable tune with cheap fuel.
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Old 07-28-2010, 01:36 PM
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yes, all you need is a pump and injectors and a tune from a tuner of your choice. Three things to think about.

1. large injectors, pump, and a tune will run about $1200
2. you will make some great power with a safe tune
3. You will get like %25 less MPG's but will also only be paying about $2.50 gal

So in the end does it pay off for you? hope this helps.

Matt
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Old 07-28-2010, 01:50 PM
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I guess I'm trying to avoid swapping anything. I don't want a reduction in MPG either.
Has anyone tried to drop E85 in the tank and tune with stock components?
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Old 07-28-2010, 02:24 PM
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Originally Posted by ipozestu View Post
I guess I'm trying to avoid swapping anything. I don't want a reduction in MPG either.
Has anyone tried to drop E85 in the tank and tune with stock components?
With E85 you lose about 20-30% MPG, no way around that.
Found this online calculator to see if you still benefit from switching over to E85.
http://etechmn.com/index.php?option=...d=17&Itemid=40

Talk to your prefered tuner and see what they say about trying to tune on stock components and E85.
I haven't seen or heard of anyone trying. Most people are going for the performance aspect of it.
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Old 07-28-2010, 02:37 PM
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The best i've been able to get out of a full tank of e85 is 200mi, and that's fwy commuting. I'm confident I could squeeze more out of a tank, but I can't keep my foot out of it, so that ain't gonna happen. Last fill up it was $2.69/gal.
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Old 07-28-2010, 08:25 PM
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Originally Posted by XxSti05xX View Post
With E85 you lose about 20-30% MPG, no way around that.
Found this online calculator to see if you still benefit from switching over to E85.
http://etechmn.com/index.php?option=...d=17&Itemid=40

Talk to your prefered tuner and see what they say about trying to tune on stock components and E85.
I haven't seen or heard of anyone trying. Most people are going for the performance aspect of it.
wow great find Steve! I say $700 a year if I run e85!
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Old 07-28-2010, 09:15 PM
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Originally Posted by 04caliwrx View Post
wow great find Steve! I say $700 a year if I run e85!
Their was another website with a similar calculator but cant seem to find it. Yeah I was doing the calculations, even if I get less miles per tank I still save money.
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Old 07-28-2010, 09:24 PM
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And that's also if the price of 91 does not go up!
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Old 07-28-2010, 09:33 PM
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91? You mean if E85 doesnt go up in cost. 91 has a better chance of always costing more compared to E85
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Old 07-28-2010, 10:07 PM
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no I mean 91, every summer goes up like .30 from what I have seen e85 stays between 2.30 and 2.50
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Old 07-29-2010, 08:36 AM
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Wikipedia explains that there is less energy per gallon of e85 compared to gasoline.

That would explain why it’s usually a drop in mileage when switching, and why you need bigger injectors and a higher flow pump for more power.
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Old 07-29-2010, 08:52 AM
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Ok let's say we think out side the box. There are many ways to extract energy from the motor. Most of those studies have been done without the availability of tuning. Compression Ratios, timing, plug temps, boost pressures. Can all be varied to change the fuel and air mixture. Instead of converting to increase power, convert to increase economy. Say you might lose 25% of the power for an overall economy gain. GM for example has the Flex fuel option. You can put regular gas or E85. How does that work?
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Old 07-29-2010, 09:44 AM
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Edmunds tests e85 in a flex fuel Chevy

I'm no tuning guru but I suppose with some black magic on the ecu you could manage to provide a little economy at the expense of power (reduced boost, leaned out fuel trims? I'm thinking of the low pressure turbo Saabs).

I'd think that to achieve the same mileage as running on 91 octane you'd reduce your power by a similar percentage. If I'm way off let me know, I'm a total noob with this stuff.
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Old 07-29-2010, 10:30 AM
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Me too, just trying to think outside the box.
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Old 07-29-2010, 11:10 AM
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^ I think if u did a Tune with low boost levels you might be able to get away with better mpg but you will still have some kind of loss. I know for a fact that u need a pump that will flow e85 and at least some Sti injectors if running low boost.
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