E-85 Ethanol

-Read- your owners manual. It says you may use ethanol up to 15% alcohol. That would be E15.
You may not use E-85. It will void your engine and fuel system warranty.

 

E-85 would also give you significantly less MPG. Miles per Dollar is what you should care about.

 

If it had no bad side effects (Toyota thinks it does) you would still be lucky to get 300 miles on a tank of E85.

 

And E85 in a non-flexfuel vehicle will have bad side effects. Think rust, if I understand it right.

Don't do it. Learn to hypermile a little instead. And combine trips.

 

Don't do it.

I'm not sure about the rust part...most of the fuel system pieces/parts are either plastic or alloy, but you still don't wanna do it.
I'd stick w/E15 or less.

Good Luck!

 

Besides the Prius not being being a flex fuel vehicle (not approved for E85), it is far more expensive for the energy content. See http://www.fuelgaugereport.com/.

Even if it worked, you'd see a substantial mileage drop due to the above. Per Test results: E85 vs. gasoline tests, the Tahoe they had got 14 mpg on gasoline and 10 mpg on E85.

 

yes perfectly save go ahead and use it. why don't people rtfm anymore?

 

so why are they selling it? just to ruin your car?

 

Selling it to help meet the federal mandate requiring gozillions of gallons of ethanol be produced and sold, thus making food expensive.

Or as I am fond of saying: "because Iowa votes first."

There are a fair number of flex fuel vehicles out there, but not so much among fuel sippers like prius.

 

If your car was E85 Flex fuel ready, (there would be a badge on it somewhere) and if the station was charging more than 25% less than E10 gasoline, then the only downside would be stopping to fill up more often.

My Prius is not E85 certified and stations near me are only offering a 20% discount, so I won't be using it.

 

For use in Flexible Fuel Vehicles | Ethanol Retailers. It seems as though it's produced due to farm lobbyists and because the government gave incentives to automakers to produce FFVs in order to boost their CAFE numbers.

I posted about some of this scam/incentive at http://my350z.com/forum/other-vehicles/221422-altima-hybrid-pics-2.html#post2848690. Unfortunately, some of the links are dead now but you can see the CR article I cited at The ethanol myth. An archive of the CR press release is at http://replay.web.archive.org/20060924164724/http://releases.usnewswire.com/GetRelease.asp?id=71591 that has the quote:

It would be interesting to see what a (currently mythical) FFV Prius would count as for mileage against CAFE. The 2011 Prius already counts as getting "70.7791 mpg" for CAFE purposes.

IIRC, the incentive will be going away in the next few years. Maybe someone can chime in about the timeframe.

 

I really like the idea of E85 because of way less emissions even though overall consumption will go up. Here the E85 is made of food waste so its also very ecological way of producing energy from recycling.

Having tanked an odd E85 tank with a mixture of half of a tank of normal gas and you can smell how the exhaust is getting cleaner. Here in Europe our main fuel is now 95E10 which has 10% alcohol.

The trick here is something called long term fuel trim. Based on articles read about using E85 it looks like the threshold for long term fuel trim setting a MIL light is around 30%. E85 as fuel needs around 35% more fuel flow so eventually 35% limit is reached over the time if running pure E85. If using a mixture of normal fuel (in our case 95E10 where 95 is rom+mon/2) and E85 this threshold limit is not reached.

The way how I see it there are two options to overcome the long term fuel trim issue:

1) Add an additional E85 enrichment unit that are commonly sold over ebay etc. I dont like this idea as the fuel consumption gauge would get off, but its easy and cost is around 200usd or so.

2) Modify sensor data that is used to calculate the target mixture to add around 5% more fuel constantly to the mixture. A good candidate would be to generate a bias in the intake air temperature to fool it to think the temperature is way cooler than what it is, or alternatively to add ambient barometric pressure bias (if prius has this sensor). This method with normal fuel will compensate the offset with long term fuel trim but would allow running E85. Have not tested this due to being just lazy - only been thinking it over about an year now, but what I know from various engine mcu:s (ECU:s) is likely to work. (My fairly serious hobby has been engine MCU tuning since early 2000's so this approach is not just an opinion.)

 

Hmm, just remembered that prius is a maf controlled car - even better, all that is needed is to set thr maf offset. Need to figure out if this is the std linear voltsge type msf or frequency. If linear voltage maf, then setting offset for e85 to make long term fuel trim need only up to 30% should be easy (i.e. The engine thinks it gets 5% more air than it actually gets and long term trim need is reduced too...). Worth testing at some point...

 

Are the injectors large enough to flow that much more fuel? Will the fuel rail & pump support the flow rate requirements?

On the Saturn Ion Redline's & Cobalt's with the LSJ motor, it was found that the #4 cylinder was starved for fuel when the software was rewritten with HPTuners to allow a wider pulse width. Many motors holed the #4 piston from running lean. The fuel system on those cars is single ended feeding the #1 injector. The solution was to modify the fuel rail to feed it at both ends.

Mike

 

Need to check the specs, but general rule of thunmb is that flow is given for 80% duty cycle. Most engines i have seen dont exceed 60% in stock config. Was it a turbo where you exceeded the injector capacity ?

Doesnt the obd2 protocol give injector duty ? I recall that being part of the data package. Thats the way to check this. Sorry for asking questions which have a simple answers, particular as i do have the canadian for prius gen2 version of prius can protocol display and obd2 tools, but interest has been elsewhere durng past year so have not paid much attention to my prius.

One could always add fuel pressure, but then again the consumptn gauge would be off.

 

Yes a boosted motor. The LSJ runs a Eaton M-62 blower. 12 psi stock but many have gone with smaller pulleys and gone over 18 psi. Mine is set for ~16 psi at 7400 rpm 3" pulley. Later on, GM came out with a turbo version of that motor but did other changes that I never studied. The software that I have (ZZP) allows the motor to run on e85 or straight gasoline with 60 pph injectors. I can't think of the proper term but I am thinking the MAP's or lookup tables are setup with a wide enough range to cover the injector pulse width necessary to run both types of fuel. It has been 3 years since I was really into modifying my car and it has sat in the garage for all that time. I forgot the real technical details of what is what. It is a very gas thirsty motor and the car is gonna be sold or traded in at the Toyota dealer next June on a new Prius It is not feasible to drive it with $4.50 a gallon 92 octane gas. It will not run on anything less than that because of boost and timing. You know what I mean Pay big $$$ to go fast, it was fun while gas was lower cost but not anymore

Mike

 

Yes, boosted are thirsty - but benefit from lower cylinder temperatures of e85.

There are so many e85 kits out there adding injector pulsewidth that can not believe running out of fuel - but its always a consideration.

Need to check what data obd2 protocol of prius has, to check this - but even more importantly need to find out if the maf sensor is linear voltage. In that case there is a simple opamp schematic to create the needed bias for longterm offset - recall seeing that already some 5-10 years ago for 300zx or something alike with maf.

I would rather run e85 as it just simply generates more power for less emissions. Absolute flow is one thing that inexperienced people look at first, but thats only secondary to less emissions and more power. Ran my motorcycle for some time with e85 and the exhaust gas was so clean compared to gasoline. Unfortunately the e85 spec defines maximum alcohol content and not absolute alcohol content. Therefore running it in a racing motorcycle was not practical, hope to make it different with my prius,

 

Have you tested your Prius to see if the computer can handle the needed pulse width increase without any software changes? I suppose it is possible as long as the injectors are not run at 100% duty cycle. I have heard of many people taking cars and running 50% e85 & 50% gasoline with zero issues as the car's fuel system can handle that much of a change without software tweaks.

Mike

 

The report written by an unicversity whose name i can not remebner about this topic suggests that running e85 has no difficulties, besides the mil light comingnon at around 200 mile mark. Based on what i have read it suggests that mil is programmed to come on when long term fuel trim exceeds 30% and as described above e85 needs 35% ( based on my experience in tuning motorcyles in dyno).

You should quite easily find the report by using google with keywords e85 and prius. Its from aroubd 2005 if i recall correctly and involves a lenghty period of using e85 in prius.