E85, 85% fossil fuel free...

[Swordsmith]

I converted my Sonic over to run E85, in part for increased power (which certainly delivered) but also in part to reduce my petroleum use.

I average 33 mpg running gasoline with 10% ethanol and driving like I normally do, which is to say hard pulls up onramps, 15 miles over the speed limit, dropping down to fourth to pass people and generally misbehaving. Driving the same way on E85, I get about 22mpg.

Driving nicely, not hypermiling, but taking it slow, shifting early, keeping the rpm under 2K as much as possible, and staying within a couple mph of the speed limit, I get as high as 40 mpg on gasoline, and on my single test tank of this strategy for E85, 31mpg.

Doing some back of the envelope calculations, I seem to be getting
normal gasoline driving, 37 mpg of gasoline
sensible gasoline driving, 44 mpg of gasoline
normal E85 driving, 147 mpg of gasoline
sensible E85 driving, 207 mpg of gasoline

Now of course ethanol isn't completely harmless, and is often produced using petroleum, so this isn't a totally fair comparison, but on the face of it, it looks like running E85 is a very green mod, at least in terms of dramatically reducing petroleum consumption.

[Quezacotl]

How you exactly converted it? Installed an flexfuel box?

[Swordsmith]

Swapped. In 42# injectors, a couple feet of ethanol resistant fuel line, alcohol sensor and harness out of a Buick regal, and a tune designed.to detect ethanol percentage and react appropriately. Pretty simple really.

[cRiPpLe_rOoStEr]

Considering ethanol energy content is around 30% lower than regular gasoline, E85 is actually 59.5% fossil fuel free. BTW here in the Republic of Bananas the Sonic is available with an E100-capable (real flexfuel) engine

[Frank Lee]

I don't do anything to my old Fords to run straight E85. Except for poor WOT response, it works.

[Swordsmith]

Poor WOT response is the opposite of what I get running E85; to take full advantage of the potential I had to install a stronger clutch, and then burned that out and had to install an even stronger clutch. E85 has less energy per volume but you can run it at a much faster timing, the equivalent of 106 octane. I've seen as high as 250 hp on my ultragauge in a car that stock delivered 138, and running gasoline with my other modifications never went higher than 195 on the same gauge. I know those aren't highly accurate numbers and don't reflect power to the ground, but they are indicative of how much relative increase E85 can deliver.

Here, though, I was more interested in discussing how much less gasoline the fuel lets me use.

I'm jealous of Brazil and its Cane ethanol, running around on Corn is nice but I know yours was developed more efficiently. And 100% would be, pun intended, sweet.

[rmay635703]

Originally Posted by Frank Lee

I don't do anything to my old Fords to run straight E85. Except for poor WOT response, it works.

As long as its cast iron nothin like lean burn at WOT

[Frank Lee]

My solution is to stay out of WOT. Most of the time I run blends so it isn't an issue then anyway.

[Allch Chcar]

Sweet. I've been hearing about the flexfuel sensors being used in aftermarket conversions. I figured it was a new/unknown thing back when I heard about it.

I think we have an unspoken agreement to keep the E85 stuff out of the Fossil Fuel free section. Even though minimal amounts of Petroleum are to make Ethanol, it's 15-30% Gasoline at the pump depending on the season. Usually we post topics under the Efficiency sub-forum or in Central.

But anyway, good to hear E85 hasn't been forgotten. I'm saving to buy a Subaru BRZ myself and the Flexfuel conversion with tune is going to be the first thing I buy for it.

[NeilBlanchard]

Um - how exactly is ethanol free from fossil fuels? An awful lot of diesel and natural gas goes into growing corn and distilling it and refining it into ethanol.