An easy 13.6%

[dwarfnebula]

The 4.0 Jeep 6 certainly can't take advantage of the ethanol because it has no knock sensor. Mine pings badly on the 85 octane they have around here, it needs mid grade. My Hyundai cares not, I've never heard it ping.

I remember hearing premium gas, even ethanol free, has fewer btus than low grade; can anyone corroborate this?

[Frank Lee]

Don't knock it 'til you try it MUWAHAHAHA.

That's odd, my friend's Gr. Cherokee straight six loves E85.

[foytix]

Pretty sure e85 should only be run in flex fuel vehicles as it's 85% ethanol. Aside from any running issues positive or negative, the fuel systems in non flex fuel vehicles are not built to stand up to that much ethanol. I know an engineer that works for Volvo (trucking division) and he explained that the main reason you don't see ethanol content higher than 85% is the extreme expense building tankers that the fuel won't destroy. That and you'll never see 100% because people would be willing to drink it LOL. I DO KNOW ethanol destroys the fuel systems in small engines and powersports engines and could go on for hours on the negative effects there.

[Frank Lee]

Oh for gawd's sake, look around here, I've been posting about running E85 in non flex fuel vehicles for about a decade.

[foytix]

We still don't have any e85 stations around here, unless you have access to a military base. Guess it's never taken off that well, at least here on the east coast anyways. Curious, what do you see as a benefit to running e85 other than increased power?

[Frank Lee]

Ethanol is everywhere in the midwest and has been in one concentration or another since the '70s.

It's oxygenated, it's renewable, and the last time I bought some it was $2.15/gallon.

Experience trumps theory and heresay.

[Miller88]

Originally Posted by dwarfnebula

The 4.0 Jeep 6 certainly can't take advantage of the ethanol because it has no knock sensor. Mine pings badly on the 85 octane they have around here, it needs mid grade. My Hyundai cares not, I've never heard it ping.

I remember hearing premium gas, even ethanol free, has fewer btus than low grade; can anyone corroborate this?

I was hoping the lack of ethanol would help. Wasn't expecting a power / mileage increase from the higher octane. Wasn't expecting it to go down!

What year is your 4.0? Mine is a 2000 with coil on plug ignition and does have a knock sensor. I don't believe the older ones (or any 4.0 with distributor) has a knock sensor. I have been able to run non ethanol 85 (from a local indian reservation) in the summer and no knocking.

Higher octane gas has less energy and is slightly more resistant to igniting. Less energy means less heat expelled and less resistant to igniting means it won't light off based on heat in the cylinder like a lower grade gas would.

My focus *may* be able to see a slight improvement from higher grade gas. While it isn't higher compression, the ECU will try to advance the timing as far as possible until it knocks.

While I don't believe it can "sense" the octane of the gasoline, it is able to get an idea of the octane by how little/much it can advance/retard the timing.

[oil pan 4]

Glad I am not the only one that thinks taking 50 some pounds of corn and turning it into 2 gallons alcohol a horribly inefficient process at least when trying to power a car with it.

The only vehicle that I tested and didn't see enough difference with E0 versus E10 was that Lincoln town car we had for a while and its 4.6L gas hog engine.
The only vehicle I cant do the test on test is the bug. It needs mid grade and I cant find any E0 mid grade gas.

[oil pan 4]

Originally Posted by Frank Lee

It's oxygenated, it's renewable, and the last time I bought some it was $2.15/gallon.

I don't see how the natural gas used to make the ammonium nitrate fertilizer, electrical power to water the crops, all the petro chemical based pesticides, non replenished aquifers that are depleted are renewable.

[Frank Lee]

They're gonna grow it anyway.