Mechanical changes needed to run on e85

To run pure e85, the only mod you need is a piggy back ECU to stretch injection duration by 30% and add even more fuel for cold temp cold starting. They are are available as e85 kits with Toyota injector connectors. No other mods required.
You may add a ECT spoofer to save fuel. Compliments well. I run both.
Marko
PS up to e70 you can run as is. Below freezing about e40

 

Last week a fellow from Germany posted on his E85 conversion with some pics:

The fuel ist made in Germany from corn, potatoes or sugar beets. And yes, it's the tax that's making all the difference. You can image why nobody is driving an F150 or a Tundra here. You are getting poor by starting the engine. So don't worry about your gas prices.

I have some pictures from the installation of the so called "ecobox E85" (about $220).



Read more: http://priuschat.com/threads/e85-fuel.98721/#ixzz2bKDzG92c
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I'd be really worried about the integrity of the rubber/plastic seals that come into contact with the ethanol. Many do not tolerate it well, which is why so many car companies say specifically that some models are E85 ready, while others are not...

 

Threads like this are why I prefer not to buy used vehicles. Carfax is great at determining whether or not a vehicle has been in a major accident (providing that the accident was reported to the police.) Carfax is also fairly good at determining whether or not there has been an insurance claim against a vehicle, or odometer fraud....sometimes.
However (comma!) there's no way to determine whether or not the previous owner was a moron who used substitute fluids and filters because they thought that they knew more about the car than the knuckleheads that designed and built it, or...somebody used their vehicle to experiment with modern chemistry.

CAVEAT:
I'm something of a proponent of ethanol.
No. It's not the shining path forward. If we converted every tillable acre in the United States to raising corn for ethanol production overnight....then it still wouldn't be close to meeting our current driving needs, and lets face it. Sex is fun!
There are going to be more people on the planet next year than there are this year!
Even if we started making ALL E100 vehicles and found a way to backfit our current automobiles to burn E100,
the math just doesn't work. Corn (or sugar cane) just isn't going to cut it.
However (comma!) I think that farmers ought to be allowed to sell their corn to whomever they wish without a bunch of whiny-a$$ed control-freaks using propoganda and bad data to obfuscate the picture...either way.
Somehow....the eco-Nazis in this country think that it's evil to burn ethanol in cars, but somehow it's better to convert corn into HFCS to fatten our kids, use it as silage to fatten our cows, or turn it into Jack Daniels.
Then...on the other side of the argument, you have "studies" like those done by "Change2e85.com" that would have you believe that you can burn E85 in your car with little in the way permanent harm---without disclosing of course that their study vehicle, while not "OFICIALLY" E85 certified.....uses many of the same components that GM uses in the vehicles that they DO certify for E85.

Me?
I'm not that much of a control freak. If you wanna burn E100 in your car?
Fine.
You'll probably get away with it, since many of the problems associated with using alky in your fuel manifest themselves over time (not necessarily miles!) and many of the experimenters out there will sell their cars after only a few years of use, meaning some other poor sap is going to get a car that was abused....instead of just used.

Bob Wilson's thread used his G2 in controlled experiment and in this thread he fully acknowledged that he was aware that his car might suffer damage from the experiments. Also....he's probably not going to sell his G2 until it had lnar mileage and is old enough to drink alky the way WE drink alky! ----so his experiments aren't what I'm referring to.

Just be aware that no matter how thin you slice the bacon.....it still has two sides. You MAY have to do a juuuuuust little bit more than change the color of your fuel cap, and manipulate your injector pulse to avoid problems when you burn >E10.
Juuuust sayin.

Good Luck!

 

There are quiet a few people running e85 in their Gen2 Prius.
The before mentioned "potential" damage MIGHT happen as he sees a check engine light once in a while. The cause of this appearing is well known. the Gen2 Prius adjusts its mixture employing a wideband lambda meter. If the ECU needs to add more than some 25% of fuel above what would be required with E0, it throws a lean mixture code.
If you run a piggy back ECU, it adds 30% fuel to whatever the Prius ECU injects. This essentially makes e85 invisible for the Prius. Your MPG meeter will read 30% low though.
I run this box:
http://www.ecobox.günstig-tanken.eu/ecobox_e85.html
I paid €95. Progamming via a windows program and USB.
There is just a hand full of parameters. They are all preset. I changed very little. Mainly normal enrichment to 30%.
As the box comes with a temp sensor that you mount somewere at the engine, I knows when the engine is cold. As the enrichment is constant above 24C, accuracy does not matter. Without a temp sensor on a piggy back, cold start will be rather bad. Ethanol has a very low vapor pressure. you essentially start the engine on the petrol content of e85 in freezing temperatures. That's why enrichement is set to 80%. It is limited to 1 minute. As the Prius has a preprogramed warm up scheme, I found this 1 minute to be all it needs.
The Prius ECU has a very wide regulation range. The piggy back should recenter fuel trim right around 0% again.

http://www.ecobox.günstig-tanken.eu/images/ecobox-e85-software.jpg

From a chemistry standpoint, E10 is approved for the Prius. If the rubber seals would have a high affinity (partition coefficient, solubility) for Ethanol, they would already deteriorate running E10.
I run it now for about 10000 miles. Coldest temp was some -5°C. Be aware that e85, I use the french e85 as it is cheaper, only has 60sh% Ethanol in Winter to help cold start. Running enough cold start enrichment, the piggy back conversion kits have that feature, they start pretty much as well as with normal petrol.

Eunning without a piggy back ECU, you need to limit yourself to about 70% ethanol in summer and 40% ethanol in winter or get the lean burn codes. No damage to the engine as it actually does not run lean. It just sees the correction is above a treshhold.

On the germay prius forum, some folks run diluted e85 for years without trouble. In the US people run piggy backed (e85 kit) Gen2 prius on e85 for years.

Boycotting e85 won't help as E10/e15 or even e20 is rolled out in many states of the US as regular gas.
Folks will burn millions of gallons of ethanol anyhow. Why not run e85? It won't make a difference to corn, farming or the world. There is leverage going from oil to corn. It has a positive energy balance. You get more energy out than you put in essentially stretching your oil.

If I would still life in the US, I'd covert to CNG. Works fine with the prius. You just lose some power.

If someone is scared of used cars, buy new ones. e85 would be the leas of my worries. Cars do mainly corrode these days in colder climates. Rust was a thing of the past until the cost cuts came in. Now they rust after some 5 years.
Corporate customers, they buy the majority of new cars theses days in Europe at least, keep cars for 1 to 3 years max. As long as they run/not rust in this time, it is fine.

Marko

 

I suspect some eco-weenie might be sneering about the 'positive energy balance' thing....and probably very quickly!
There's gold in them thair rows.....and it's competing with the black gold that's in the ground!
I'm sure that trying to determine which side of energy neutral corn really comes down is going to be a function of funding and passion more than truth.

 

Thing is for me in particular, I have the lowest fuel costs running e85 as I can buy it in France where it seems tax free. I live close to the french border. I get it for €0,90 per Liter vs €1,10 per Liter in Germany. Regular fuel is about €1,60 per Liter. Add the 30% extra consumption I end at 1,17€ per Liter equivalent fuel cost per Liter. I save some 25% on gas!
That is actually a very american way of thinking. I get what I can buy the cheapest. That the stuff is not from the middle east is a freebee.
Now CNG is even more cost efficient, but requires that €3000 conversion vs. €100 piggy back ECU for e85.
In my cost model and the miles/profile I drive, e85 even beats a plug-in conversion and CNG.
If I would have to pay €1,10 a liter, it would pretty much be not worth the trouble anymore.
There is little eco-trehugging in this for me. It comes down to $ per mile driven.

If it does not make sense from a cost standpoint, I would not do it.

PS The French cash in billions of Euros of EU farming subsidiaries (the most in Europe), mainly paid actually by the German tax payers. This way I can get a little bit of this back.
Sometimes you can smell what some of the e85 in France is made from while filling up: excess cheapo Wine and fruits.

Marko