How does this help if the energy content is lower?

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01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

Even though the BTU are lower the cetane of most biodiesel is higher. So with low blends you get an improvement in lubricity and cetane. I can copy the links to you if you want to read more about it.

Chris

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1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

I remember reading about that. I thought that BTU being equal, higher cetane is better. However, if the BTU of bio is less, how does the cetane help other than in the sound characteristics? IOW if 1 gal of diesel has say 1000 BTU but 1 gal of bio has 900 BTU but D2 has 45 cetane and B100 has 50 cetane, how does it help?

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

I'm not a chemist so I can't answer your question. I just have just read about low blends and lubricity on the biodiesel forum. I do agree with what guru said about no service members having to die for veggie oil.

Chris

__________________
1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

The reason I am not sold on the lubricity issue is that I have yet to see data on ULSD having less lubricity than LSD. Getting rid of the Sulfur takes some of the lubricity out. At the same time, lubricity agents are being added to make it come to the same standard of lubricity that LSD has. So, for all practical purposes, if all things are done the way it should be done, there should be no difference, lubricity wise between LSD and ULSD. It should have the necessary lubricity properties at the pump (not at the refinery) as LSD. Now, unless someone can show me that the agents haven't been added more often than not, I can't see why there would be any lubricity differences.

YET. The history of mankind has been constant fighting over one thing or another. As I have said before, even if we don't use one drop of oil but our major players do, we are still going to have to fight because if it affects them, it will come back and bite us sooner or later. We don't live in an isolated world anymore. Just like your neighborhood. You have a cesspool in your yard and it will affect me. So, unless I can stop everybody from using oil, nothing we do will make a difference other than we can achieve a Pyhrric victory.

Edit: The only way I know of to keep off the oil taint is to move to the mountains and live off the land. Everything you wear, drive on, eat, etc, etc, has the taint of oil. Use it and you are using oil in one form or another. Just like if you use gas or diesel, you are using oil in one form or another. Waste it and you are wasting oil in one form or another, IOW, you made that serviceperson die for nothing.

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

On the lubricity issue, I work in a refinery and I’ll tell you what I see. There is a spec for lubricity, additives are put in the ULSD in order to meet the spec. Now, these additives are expensive so you can bet we don’t put any more in than is necessary to just meet the spec.

The old LSD easily exceeded the lubricity spec so you got a fuel that was much lubricating than what you have now. Maybe it’s more than we needed. I don’t know. Hopefully the spec is set where it needs to be.

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1982 300TD 279K.
1984 190D 5sp 265K

But it does meet the required spec and thus it will do the same at the pump, right?

I thought that LSD was what the spec was based on? If so, how do you exceed that spec with LSD? Not doubting you but just curious.

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

IIRC, the cetane value is a measure of how readily the fuel will autoignite. IOW, a higher cetane value fuel will compression-ignite easier which may be the difference between starting and not starting under marginal conditions (temp, compression, spray pattern, etc). I'm sure there are practical limits to this relationship also but I don't recall just now. (College was too long ago.)
The heating value of the fuel (which, btw is about 19,000 btu/lb for diesel) will not affect how readily the fuel ignites or burns (gasoline is about the same HV) it will just affect how much fuel you have to burn to do a given amount of work.

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1983 M-B 240D-Gone too.
1976 M-B 300D-Departed.

"Good" is the worst enemy of "Great".

Regardign cetane, as empirical proof, the 225K mile 606 was pinging, Power Service Cetane Boost did the trick, and also cut power to some extent. ( hard to tell as the A/C has been on alot lately and it also cuts the power down!).

I went from a 65% bio blend and now the tank is likely 25% bio, and the preignition is still at bay. No more rattles when passing on the highway.

Trying to find the right mix, sicen I;m " beggign" for bio right now. None sold here, only home brewed. Excellent supplement and keeps the lil diesel I have very quiet and happy.

BTW, as an aside, higher octane fuel also generally put out less BTUs. I often tell guys who have built custom gas engines to use the lower octane the enigne requries for best power. Putting 100 octane, or even 93, in an 8:1 gas engine which likes 87 will LOSE pwoer. It will make MORE POWER on the 87 octane.

The cetane relationship ( which I have little emprical data on) msut be similar. The way to really use bio,especially bio made from tallow weith a cetane of 70, is to bump compression, assuming static compression has the same effects on a diesel motor as a gasser.

Heck with 70 cetane fuel, you could run 25-26:1 I should think. More power, but with the higher combustion temps, NOx emmissions will be greater.

But the higher cetane fuel used in an engine that can use a lower cetane will generally make less power IF the same relationship holds as octane. Its not as counterinutitive as it sounds. Cetane and Octane make the fuel less reactive.

ASSUMING I am understanding the cetane rating correctly.