Are you certain of this? Tuning for the fuel with the least amount of ethanol would simply be a straight gasoline tune.

I thought adding more gas to an Exx tune would make it richer.
E10 to E00 = more gasoline % = richer mix when on an E10 tune
E85 to E70 = more gasoline % = richer mix when on an E85 tune

I don't see how running more gasoline % on an E10 or E85 tune could make is run leaner.

That was not the case in any of these examples:
Reference #1
Reference #2
Reference #3

 

True about fuel, but boost and timing will have to be set for lowest ethanol content fuel when running a single tune.

 

When boost rises my car runs leaner mainly noticeable up top. the cool part about e85 is it can run leaner than gas without knock and is reported to have cooler burn

As it stands I have gone from 22-28 psi with no real change in mapping. Maybe I am not maximizing the tune and it should be noted I was rich up top before (like 10's and stock afr's)

 

You'll be scared at how much you can advance timing... Should be similar to timing map on 110 leaded...

 

Got 17.5 mpg on a road trip today driving as smoothly as possible at 65-70 mph into a pretty steady headwind. Roads were gently rolling. I'd like to be able to get this up to 20 mph, but not sure if its possible. I've already advanced the ignition quite a bit. I can lean out the afr to 15.7 which should give me +1 mpg. Maybe I can tweak the MIVEC a bit and put a little more air in the tires for road trips. :-)

 

This will help alot. Also all those hyper milage techniques works as well. The best on Gas I've ever got from Fl to NY was 34mpg. That was using the boost gauge as a throttle position sensor and staying in the vacuum zone.

The hardest part was being patient and working the throttle without boost to get the car up to 65mph, playing with gearing and down hills.

Glad mpg is a concern and that there are people practicing good driving habits.

 

Yeah, I stayed off boost except when I had to pass a few times on two lane roads. On my drive with a tailwind home I was on track to get 29 mpg on gasoline, so I think I can definitely reach 20 mpg on E85 with a little more work. I may end up carrying a 1-2 gal gas can of E85 in the trunk to be sure I have enough range to get to the next E85 station.

 

Thanks for bringing this up, MrFred. I have been toying with the idea of doing the same, but have not found any good info concerning how to do so safely. Due to the extreme heat here, I'm sure there would be a lot of expansion of the fuel and therefore fumes. I presume any can would need to be vented. So sitting in the trunk all day in the hot sun, I'm presuming the car would be filled with fumes.

How would the fumes affect driver and passenger? What about ignition of the fumes?

 

Truck drivers in CA. add 40 gallon tanks to the bed of they're truck so they can fill up in mexico for 1/2 the price..We should do the same

 

The vapor pressure of ethanol is lower than gasoline, so there wouldn't be as much pressure build up. I'm pretty sure that it would be reasonably easy to find a container that would not leak fumes.

 

Every gas can I've ever seen has a vent for this very reason.

If it was sealed, that sounds explosive to me. Or am I just being a baby.

 

Usually there is a cap of some sort to seal the vent. That's how it is for the several gas cans that I have for my lawn mower and weed whacker.

 

Ok I know this is a stupid question I'm kinda confuse, so do I have to tune my car to put the e85 fuel?

 

You need more fuel delivery and bigger injectors

Short answer=yes

 

It's not a stupid question.

Your answer is: yes. You do need a tune.
1. Injector size needs to be upgraded by approx 30% minimum.
2. The ECU needs to be re-calibrated to make the best use of the 105 octane fuel.