There is some good info and some bad info in here. Ive been running and tuning 400+whp cars on e85 for over 5 years now. All my friends run e85 in there high HP cars.

1. There is a loss of 10-20% in MPG if running straight e85. At WOT the air/fuel misture will need 30% more fuel than gasoline to get a good air/fuel mix. So if running pure e85, if your ECU cant compensate up too 30% fuel/air change than you will run lean at WOT and start to eat up valves. Yes it may take a long time since we dont run 4runners at WOT that much but on my talon it could eat up a valve or piston in a madder of a few WOT runs. So if switching over too pure e85 you want to have something to control the fuel/air mixture.

2. You dont make power just switching too e85. I have dyno tested this and so has lots of other people. If you car was running real low octane causing detonation and your timing was being retarted then yes you will gain power but that would happen only if running too low of octane for the car to begin with. You only gain power when you add timing, compression or boost to the motor and e85 allows lots of all those things. It never detonates/knocks and you can actually lose power from adding too much timing since it never detonates.

3. You dont need to upgrade fuel lines as long as the car is made past 1989. Thats when they started adding 10% ethonal to gasoline and asked all car manufactures to make stock rubber lines e85 safe.

To run e85 safe

1. You need some time of fuel management and a WBo2 so you can watch your AFR's and make sure your running safe.

2. If running boost you will need to upgrade fuel injectors and fuel pump to handle the added fuel at WOT. Usually around 30% more fuel at WOT and 20-30% more fuel at cruise and mid fuel trims.

3. You will need to pull injectors every 10k miles to have them cleaned. E85 has some type of addative that gums up the fuel injector tips. It can get so bad that the injector can fail and in our high HP cars its usually very bad at WOT on the track. You can either clean them or run gasoline sometimes to get the goo out but you will need to retune too do that.

If anyone has questions running e85 send me a PM. I dont have knowledge running it on our motors but I have extensive knowledge tuning and running it on other vehicles making lots of power. My talon was running 32psi on an holset HX35, 12.0 AFR (lean for that much boost) and over 24* timing with zero detonation on a stock Mitsubishi 4 cylinder block. E85 is awesome stuff!

Thanks for the info Jay. Like I said, I'm far from an expert. I've just read a bunch. I still may add the kit, which will allow me to run both E85 and regular gas...even just mixing will save some money. And for $375, it's not the most expensive mod I've done to the truck!

If you can get the fuel substantially cheaper, then it may be worth it, but you need to consider that you will get 10-20% worse fuel economy than funning E10 fuel, so the E85 needs to be cheap enough that it still makes sense after the cost of the conversion kit.

You will also make less power running E85, it's a lot like a LPG conversion in this way.

Interesting - it's sort of the flip side of the diesel conversion. Small diesels typically get 30-40% better MPG than an equivalent gasoline engine, but the fuel is also typically quite a bit more expensive (I've seen stations around here where Diesel is as much as $0.90/gallon more than regular unleaded.)

I actually owned an E-85 capable vehicle, my 1999 Ford Ranger with the Flex-Fuel 3.0 V6. Unfortunately, that was before the big corn lobby subsidies so at that time (1999 through 2003) E-85 was actually 10 to 20 cents/gallon more than premium unleaded, and therefore there was no incentive to run it.

I did pump a tank full of E-85 a couple of times just to see how it worked. I could not tell any difference performance-wise but MPG dropped by about 10%.

Back in 2008, last time gas prices spiked, I looked into this briefly for my Tacoma. Ultimately I decided it wasn't worth it. However, I'd be interested in seeing how this plays out.

Did a little analysis. The assumptions are that the setup cost is $375 and that the average prices are as shown below, per AAA website, yesterday.

You will have less MPG and less power.
It does burn cleaner but has less power potential. True, there are high powered E-85 vehicles (500hp) but more power can be obtained with pure gasoline.

As of this morning, E85 was 90 cents cheaper per gallon at the station near my house. This time of year is when E85 is highest, and it will continue to go down heading into harvest in the fall. I've seen it at time for $1.30 cheaper. Someone else posted its a $1 and some change cheaper in Cali right now. I'm getting around 19mpg now with E10, so to get around 16mpg would not be that bad for me. My last truck got 12mpg, and I had that damn thing for 4 years!

Nice work! Millerrad seems to be able to get E85 at a bigger discount than you've shown here, but there is much that can be shown from your work here.

So basically, assuming a best case scenario of only a 10% fuel economy decrease compared to E10, the breakeven point is 35,000 miles using your fuel costs, and if the fuel economy loss is 15%+ the breakeven point is beyond 108,000 miles. If the 10% decrease was realistic, the money saved is about $733 over 108,000 miles (can we safely assume this is in excess of how long you plan on owning this truck?).

Hardly seems worth it, to deal with worse power from what could be considered an underpowered truck in the 1st place.

I'm sorry, but ethanol gets lumped in the same category as electric cars for me, it's a neat idea, but it just doesn't make sense.

Yes. I more did it because I was curious. For the 15% and 20%, it was negative all the way to 200,000 using the current e85 price. I have the usage in a spreadsheet too, just didn't take screen shots of the whole thing.

I wonder what it would be like for a NG conversion. I wish I could get a solid # for the conversion cost, and I would do the analysis. I have heard ranges from $800-$3000.

Think of it this way. E85 is 30% less dense than gasoline so too get the same AFR's you need roughly 30% more fuel. Meaning it can be worse than 20% loss in fuel economy. In my Talon I used to go WOT a lot and I went from 320-350 miles per tank to around 200-250. Usuall more around 220 miles per tank. It was a huge loss but well worth the 100whp increase I was able to make with more boost, timing and compression.

Also those $345 ebay kits are not the best. It just tricks the ecu into leaving the injector open longer. You really want to do it right and add some type of engine management to control the fuel and timing. E85 loves extra timing. Not to mention adding a knock sensor to be real safe. I have always tuned with a knock sensor. I plan on turbocharging and running e85 sometime in the future on the runner.

Thanks for the 411 Jay.

Might have to invest in a Haltech system.

Do you think a SAFC well suffice for timing and feuel mixture, or is a standalone a way to go?

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Watch this movie if you get the opportunity.

You will realize that fuel economy only matters as far as range. Oil is a finite resource with an increasing demand, and potential for insane price increases. Alcohol as fuel is a renewable resource with no negative impact or downside other than less total range per tankful, and less money as profit for the oil empire. Alcohol is not an import, and is much cheaper per gallon than gasoline when sold by an independent fuel distributor.

I am seeking this conversion for my gen4, probably from https://www.change2e85.com/index.php?route=common/home

I am interested in converting to flexfuel on my 2003 V8 4Runner. Naturally aspirated. What is the best thread for this? Has anyone done it?

Instead of creating a new thread regarding 4th gens, you bump a 9 year old thread about 3rd gens?

In vague general theory, you cold put injectors on with about 25 - 30% more flow and let the stock ECU figure out the rest - the narrowband O2 sensor will find stochiometric regardless of fuel, all it's looking at is left over oxygen.

But the big sticking point is that E85 is 'up to' 85% ethanol, it's not '85% ethanol'. So going in with an assumption that you're going to get 85% ethanol will not work out well. It could be lower on any given day at any given E85 pump. Much lower. And then your engine will run rich, hit the limits of its O2 sensor driven compensation, and set a CEL.

What the system needs is a flex fuel sensor that can tell the ECU how much ethanol is in the fuel, so it can adjust it's flow calculations correctly. But that can't happen with a stock ECU. And if you go to a standalone that can do it (I'm familiar with Megasquirt, I have that on some modified turbo cars), then it will NOT leave OBDII functional, which may be a problem depending on your jurisdiction and year of car. And *scroll up* 2003 car in California, lol, yeah, that's going to be a problem.