Pure Gas ( No Ethanol ) experiment

That doesn't appear to be the case now. In 1972 a friend of ours ran his Mercedes 220 diesel and Deutz air-cooled tractor on fryer oil from one of the food joints. Both ran well, and this was just processed through a filter. Now, the biodiesel is much more refined and has a few advantages for diesel engines - greater lubricity (which is important since removing sulfur from the diesel fuel reduced lubricity), and high cetane rating (diesel equivalent to octane). Downsides - it gels more quickly so has to be heated in the filter.

Because of the way my VW TDI heated the particulate trap to burn off soot, with a series of injections of diesel into the exhaust stroke, that vehicle was limited to 5% bio-diesel to prevent oil contamination due to piston ring leak-by.

Many of the complaints about bio-diesel come from truckers. They typically buy fuel all over the country and I'm sure they've gotten some bad fuel, whether bio-diesel or conventional diesel. Cold weather performance is also important to them. For a farmer, much of their tractor work is done in the warmer months.

 

The difference there is likely in the detergents and other additives.

Toluene and xylene have less energy per mass than octane and other compounds making up gasoline. Plus, ethanol was being used as an octane booster before the mandate. Then there is the variation between refineries, crude, and seasons; the butane added during winter drops the energy content.

There is no such thing as pure gas.

The only car I tested different octane ratings in was the Sonic. It did get better fuel economy with higher octane, but it had the turbo engine that was designed for the higher octane fuels in Europe. GM labeled it as regular fuel here for marketing.

Biodiesel is a better cleaner of the fuel system. If an engine that ran mostly diesel, there is a build up of gunk the tank that the biodiesel breaks free and can cause problems clogging things.

I think all the European brands use the same design for regenerating the DPF; they all have that B5 limit. Ford and GM have a B20 one, so I think they directly spray the fuel into the exhaust before the filter.

 

Oops. Typo.
"octane" is not a compound.
It is a measurement scale.

 

It's both.
Octane - Wikipedia

The compounds are single bond chains of eight carbons with hydrogen filling in the available spots.
A 100 octane rated gasoline has a resistance to compression ignition equal to that of pure iso-octane.

 

"Octane" is colloquially used as a short form of "octane rating"

Nobody reading this kind of a forum needs to know the "dirty details".
It only confuses the issue.

 

I like details. And it didn't confuse me.

 

How much octane is used in 1 parsec?

 

I laughed & laughed & laughed when I read that....

Good one


Rob43

 

Higher Octane is often (though not always) necessary for a boosted (super charged or turbo charged) engine to avoid pre-ignition. There are knock sensors in the engine to put that boost right on the cutting edge of what they can get away with. The upshot is that your Super Charged Previa (yup, used to own one of those) has more power AND gets better fuel economy than the regular Previa. If you put regular gas in the Previa it will still run but lose efficiency and power as the super charger can't be called on as much or the ignition gets adjusted to prevent knocking. This can be bad for the engine if it is not designed appropriately and why most high performance vehicles in the 70s require the use of higher octane.

This is a two way street though. If you put premium in your Prius it will have the exact opposite effect. The ignition will have to be adjusted to get fully burned fuel and you will see mileage decrease. It will also develop less power. Plus it could lead to reduced life of the engine. The real question is will you notice the difference? Probably not. But the one thing you will definitely notice is that your tank costs an extra dollar per fill up. Literally the only point of "premium" gas is to prevent pre-ignition in a high performance engine.

 

I tried premium in our 2012 Prius v a few years ago. Did not see any improvement in mileage, if anything, maybe a little worse. I won’t be using it in my Prime.

 

The one reason I can see to use highest octane is to avoid ethanol, which is possible, up here in Canada anyway:



I undertand in the States highest octane gas is still 10% ethanol, usually? But as you say, the sand-pounders: the higher octane could well reduce your efficiency, and the price...

Ethanol-free, regular octane: the holy grail?

 

For most average drivers, there is NO reason to try and avoid ethanol. NONE.

So then, the only reason to use E0 is if the additional cost is less than 3%......which it almost NEVER is.....and certainly never is if you have to jump from regular to "premium" to get it.

 

I do not agree totally. In Canada I am not sure what regulations you have for gasoline composition.
95 E0 could be juicy for MPG. US regulations tend to minimize energy (MPG) for the goal of clean burning.
But if I Ilved up there, I would try it to see if I thought it was better, assuming it was cost effective.
If it was not cost effective, I'd just try it a little bit.

 

I tried running the tank fairly low, then refilled with that top octane chevron (ethanol free) with no discernible change.

Did get a tank of Chevron regular, up the coast one time, that was miracle fuel, maybe ethanol free.

 

There are 14,149 E0 sources in Canada & the U.S. Ten(?) years ago, Michigan had less(?) than one half the E0 sources of my Washington state. Now with 460 E0 sources, Michigan has 150 more E0 sources than WA state. However, a large majority of Michigan E0 is only available in higher & high octanes, whereas my state has quite a bit of 87 octane E0 available. When I use E0 for my low compression ratio gasoline engine, I use 87 octane E0. Already 87 octane E0 gasoline has a 3 point increase in octane, as compared to 87 octane E10 octane, which has its gasoline component only at 84 octane. My last five 87 octane designated, low compression ratio engines (with years of both E0 & E10 usage) have gained 8%, 8%, 7%-8%, 7%, & 5% better MPG, 87 octane E0 vs. 87 octane E10.

 

That is a ridiculous statement to make.
It is the TOTAL that counts, not what ingredients were used to get there.

 

Pure ethanol provides 2/3 of the heat value available in pure gasoline. If you cut it, you still have less energy per unit. Does it still work, yes. Do most of us have a choice, no.

 

In truth the oil industry loves ethanol in their gasoline stocks. First, it takes lots of oil to make ethanol. Second, lots of oil is used to support the "ethanol in gasoline industry". Third, lots of oil is used transporting ethanol to blending facilities. Fourth, by adding only 10% ethanol to gasoline, MPG in 87 octane, low compression ratio gasoline engines is lowered by 8% to 5%, thus drivers fill up with E10 8% to 5% more often. In total, more oil is used than E10, erroneously, could save.

 

Sam spade hovers over these ethanol threads.
Nah. Erroneously designated 87 octane E10 is comprised of 10% 114 octane ethanol plus 90% 84 octane gasoline component. Neither component of E10 is 87 octane. That is why correctly designated, 87 octane E0(100% 87 octane gasoline) has 8%, 8%, 7%-8%, 7%, & 5% better MPG, than incorrectly designated 87 octane E10.