With an octane rating between 100 and 105, the performance benefits of E85 are obvious. The question is, can we tune for that high of an octane and still be safe on 92-93 when we can't find the good stuff? I'm looking at getting EFI Live and wondered if anyone had thought of E85 yet...

 

You have 2 octane tables to run off of. You could adjust one for e85 and then the other for 93 octane. I'm not sure if that would work perfectly or not. The flex fuel trucks have a sensor that tells the computer what fuel you are running. I dont know if that sensor would cause issues. Also if your lowest octane table is set for 93 you could run into trouble if you get crappy gas and don't know it. I would probably run a seperate PCM for the 93 since it seems like you wouldn't need to use it very often. Just swap PCMs when you run less than the 100+.

 

do you have a flex-fuel vehicle? as far as i know, it's hazardous to your fuel system on gas, and it needs a different mixture than 14.7. Flex fuel vehicles run a sensor to calculate the ratio of ethanol to gasoline in the mix.

 

No, I don't have a flex fuel vehicle, but then again neither does the state of Iowa for most of it's vehicles that have run E85 for the last 10+ years!!! They run regular Dodge mini vans, regular Vulcan 3L Taurus's (NOT the FFV ones), Lumina APV's, Ford and Dodge pickups... all on E85. I'm going to check with the DOT mechanics that work near here and find out what they do (if anything) to those vehicles...

 

I wouldn't suggest running E-85 in a standard vehicle. Blown '02 is correct, E-85 doesn't run at 14.7:1, in fact this is entirly too lean. Living here in the midwest, the local news channel did a test a year ago or so with two identical chevy flex-fuel trucks. They ran one on E-85 and the other on regular 87 octane. These two trucks had the identical amount of fuel in each and they were driven around the county fair track at like 45 mph to see how far each would run. the E-85 truck barely did 2/3 of the laps of the regular gas truck. So the verdict was that running E-85 didn't save you any money. Also, doen't the ethanol destroy rubber fuel lines and o-rings and such?

 

Silverado: Gas= 15/19 E85= 11/14

Today's local E85 price: $2.10

E85 to go 100 miles at 11 MPG = $19.10
E85 to go 100 miles at 14 MPG = $15

Today's premium price: $2.89

Gas to go 100 miles at 15 MPG = $19.27
Gas to go 100 miles at 19 MPG = $15.21

As E85 becomes more available, the price will go down. As production methods improve, the price will go down. I'm not saying we're going to see a buck a gallon or anything, but it is nice to have increasingly better options being forced out of the transportation industry in order to keep internal combustion alive.

I don't know about you all, but I can't see myself driving an electric car any time within my lifetime... It would be kinda embarrassing to be going down the road making fart/motor noises as I speed up while remembering "this cool truck I used to have way back when..."

Ethanol doesn't destroy rubber fuel lines at all that I've seen or heard about. Heck, I've run the cheapest gas here in Iowa, which happens to be mid grade 89-90 octane ethanol blends, ever since high school (15 years ago) without any fuel related problems. The reason it's cheaper here is because Iowa doesn't tax it as much since it's a renewable Iowa resource. Ethanol will, however, make the clear plastic style lines used on a lot of lawn mowers/snow blowers/etc brittle and that's why ethanol blends aren't recommended in most of those types of engines.

 

what kinda afr would you want to run at wot with e85??

 

I spoke to a dyno tuning shop in St Louis a couple of weeks ago and he ask me if I was interested in him tuning my truck for E85. He said that he could run a lot more aggressive timing tables with E85 due to the higher octane. The big down side is that it would HAVE to have E85 and couldn't be run on gasoline anymore.

E85 isn't that common around here so it wasn't an option for me.

He did also say to expect a 30% drop in fuel milage and that my fuel system would have to be capable of flowing 30% more than it does now on gas. I could see this being a valid option, at least for supercharged vehicles, in the future.

 

Not to mention that the amount of oil energy used to prep the fields and harvest the corn offsets any oil-savings gain. E85 is only economically viable right now because of the government subsidies...

 

After the discussion on another thread about how much of a gain running 93 octane premium would make, I decided to try it out. I had been keeping a good average of my last two tanks on "as cheap as I can find it" 87. I was averaging 15.3 by manual calculation and 15.4 according to the avg mpg function on my display. Then I switched to Shell 93 octane. I ran two tanks worth and averaged 14.9 to 15.0. Then I read a sign at one of the Shell stations "10% ethanol blend". What a ripoff, since I was still paying $3.09 a gallon.