The big problem (and the only thing holding me back from doing an electric vehicle conversion right now) is the fact that I live in northern Minnesota. Looking at Weatherbug and The Weather Channel Desktop it is Zero degrees F right now. I believe that works out to -32 degrees C. Just last week we had windchill taking the temps down into the -50 range.
Look again at the temperature/performance graphs for nickel iron batteries. They work fine at -15C.
The thing that's holding me up is that the wife is putting this house up for sale, giving me a whole raft of new jobs. But she's looking at smallholdings, so it's all good.
Now granted, if I had half an idea how to adjust any of my vehicles so they would run (normally) on ethanol, they'd already be doing it. But everywhere I've looked for info on it basically says if they don't run on it now, they never will.
Ethanol yields about 27Mj/kg, or 21Mj/litre; but octane yields about 48Mj/kg, or about 36Mj/litre. So you'd expect to see a big difference in fuel consumption.
To run a car on ethanol, you need to either re-jet the carburettor or re-program the fuel injection. The aim is to get the correct amount of fuel to the correct amount of air.
New cars can sometimes do this by virtue of the gas sensors on the exhaust. For an old car, you'd need to do the conversion by changing the jets.
The gas sensors in the exhaust don't always work very well, especially on high mileage cars. You might find that if you changed these sensors, the cars ran better. Does the manufacturer expect them to run on E85?
As for Deisels, well that's another whole different story. The only oilburners I have available to me around here are HUGE (Ford F350 Super Duty, Dodge Ram 3500, etc) 4X4 pickup trucks, or ancient pre-80's Volkswagen Rabbits.
As for diesels, the Samurai would take an engine from a 1.9 Peugeot diesel. Many people have reported that this engine runs on SVO with no problem.
Almost all modern diesel engines (and some old ones, like the Lister) run just fine on fatty acid esters. Esterifying rapeseed (canola) oil with ethanol is considered to be a bit fiddly, but rapeseed oil and ethanol are both available to the ingenious smallholder.
I suspect that again the problem is where you live -- you are too close to the malign influence of Detroit.
Sorry about that. :-(