87 Octane Ethanol Free or 90 Octane Ethanol Free??

[rmay635703]

Originally Posted by Tahoe_Hybrid

i would not use it in a newer car your just asking for trouble... 1% biodiesel caused some pretty bad damage..

https://web.archive.org/web/20150111...and-myths.html

Based on the amount of heavy ends in modern summer gas we already have diesgasohol

Any hydrocarbon mix is allowed in gasoline as long as it meets the octane rating, (biodiesel is not considered a hydrocarbon)
that is why oil companies love ethanol because they can sell you your 84/85 octane kerosene mix with ethanol to boost its rating.

Also many common injector cleaners are just diesel fuel in a can.

An Insight isn’t exactly modern either (I have collector plates on mine) but it is efficient

[Natalya]

Anyone want to guess what the BTUs per gallon of Techron additive would be? I put two cans of it in my tank (40floz total) at the start of my last gas tank because of intermittent jerkiness at certain speeds and very intermittent (months between it lighting up) P0420 even though I have a (correct for this vehicle) new LAF sensor with less than 10k miles.

My most recent tank (even directly adding the Techron to the tank measuement as though it were exactly the same as 87 ethanol free gas) was my 2nd best ever. I filled with 90 Octane Ethanol Free this time around, we'll see what I get but I'm off to a good start with 90 on the FCD over the first 50 miles.

[cRiPpLe_rOoStEr]

IIRC a small-displacement engine tends to tollerate more a lower octane rating even with a comparatively higher compression ratio.

[Piotrsko]

Small engines tend to revolve faster so you are into the timing advance and flame front limitations to prevent knocking.

Techron could be doing so many modifications to the fuel, it is hard to say what is happening. Could have fuel thinners, octane enhancers, assorted solvents, who knows? Someone was touting the addition of 1oz acetone per tank as a surface tension modification.

[serialk11r]

Thread is kind of old, but what's the purpose of this?

If you want maximum mpg just for bragging rights, you want the highest BTU/gallon mix that barely hits the octane requirement. That means mixing something high octane like toluene or paraxylene with diesel. ECUs are generally programmed to only use spark to compensate for knock, so you'll lose efficiency quickly if you drop much below the recommended octane rating.

I don't think ethanol free 90 is going to beat 87 in terms of cost, but if you're going to add 90, you can mix in a tiny bit of diesel to bring the octane back down.

Biodiesel harms cars because it has methanol, while normal diesel should be fine, I think.

[cRiPpLe_rOoStEr]

Originally Posted by serialk11r

If you want maximum mpg just for bragging rights, you want the highest BTU/gallon mix that barely hits the octane requirement. That means mixing something high octane like toluene or paraxylene with diesel. ECUs are generally programmed to only use spark to compensate for knock, so you'll lose efficiency quickly if you drop much below the recommended octane rating.

To which extent the lower-octane fuel blend might be so effective is arguable, as a much leaner fuel trim in order to benefit from the higher energy content may lead to knocks.

Biodiesel harms cars because it has methanol, while normal diesel should be fine, I think.

Pure methanol tends to be more harmful, plus most newer car fuel systems and replacement parts such as fuel hoses are now more resistent to alcohols in general.

[serialk11r]

Originally Posted by cRiPpLe_rOoStEr

To which extent the lower-octane fuel blend might be so effective is arguable, as a much leaner fuel trim in order to benefit from the higher energy content may lead to knocks.

Fuel trim is based on measured stoichiometry. What you just described is impossible.

[cRiPpLe_rOoStEr]

Originally Posted by serialk11r

Fuel trim is based on measured stoichiometry.

Sure.

What you just described is impossible.

Why would it be impossible?

[101Volts]

What's the cost of E0 where you are? It's 70 cents per gallon higher than E10 here, so it's not worth it to me, unless I'm storing a car or other engine for weeks or months without using up all of the gas. I only saw 3/4 of a MPG better with E0 (90 octane) in my 05 Explorer, BTW.

[cRiPpLe_rOoStEr]

IIRC the only E0 gas available in my country is AvGas, but it's out of question due to the lead content.