Don't mix biodiesel with diesel in your tank.

[anahata]

HB,
There are many places to research 'occasional' use of B-100 here and much has been written. I am far from a guru but am an avid reader of the forums. My understanding is that good B-100 is a great fuel but seals on (edit) injector pumps on cars old enough to have run on regular LSD are prone to failure when switching between fuels - because the different fuels contain different aromatics and/or aniline which variously swell or shrink the seals stressing them when fuels are substantially changed.
I haven't seen a decisive conclusion as to whether or not it is 'safe' to go from one extreme to another with IP seals that have only seen ULSD and Biodiesel. My seals ran all three fuels and eventually leaked. So, it will not harm the engine but the IP seals could be another story.

http://forums.tdiclub.com/search.php?searchid=4320890
http://forums.tdiclub.com/showthread.php?t=157540

I would pick a blend and stick with that blend myself even after having new seals put on the pump and only running ULSD. It is said that IP's with seals that have only pumped ULSD are less vulnerable but I don't want to take that chance. I too am interested in any further light on this though I don't want to divert this thread.

Back to topic...FWIW I live in Arizona and have been splash blending to equivalent of B-5 for 4 years (it's cheaper! AZ petro sells B5, B20 & B99 but am not sure how they blend it) I too was under the impression that Biodiesel is MORE dense and not less dense than Dino. This would be a major decider in which fuel to add first if one is splash blending. Any conclusive answers about the relative density question?

[b4black]

Originally Posted by UFO

Please correct me if I am wrong, but this specifies WATER by volume. Regardless of how it is captured in the fuel, you are limited to 500 ppm. How is that not a total water specification? How are you going to get ASTM spec fuel that drops water when mixed with diesel?

It says right in the passage you cited that they are considering replacing - that means they haven't done so. This dissolved water spec you keep referring to doesn't exist. And a dissolved water spec doesn't make sense when dissolved water is not a problem.

Originally Posted by UFO

It is ridiculous that a scenerio where water comes out of biodiesel is postulated, with zero evidence, it is required to refute it's opposite.

No idea what this means.....

[UFO]

Originally Posted by b4black

It says right in the passage you cited that they are considering replacing - that means they haven't done so. This dissolved water spec you keep referring to doesn't exist. And a dissolved water spec doesn't make sense when dissolved water is not a problem.

The existing spec is total water. Just because they test it with a currently inadequate method, the spec is 500 ppm.

You tell me, is this a semantics issue or you think there is a water issue with ASTM biodiesel?

[b4black]

Not semantics. The different between dissolved and free water is a very important destinction. Free water is bad, dissolved water is not.

Once downstream of the refinery, free water can be controlled, dissolved cannot.

ASTM requires that fuel not be hazy. That controls water for the most part. Why do you think the current method is inadequate?

[UFO]

Originally Posted by b4black

Not semantics. The different between dissolved and free water is a very important destinction. Free water is bad, dissolved water is not.

Once downstream of the refinery, free water can be controlled, dissolved cannot.

ASTM requires that fuel not be hazy. That controls water for the most part. Why do you think the current method is inadequate?

It sounds like semantics to me. Do you dispute the spec is 500ppm? Do you dispute the spec is separate from the testing method? Obviously the spec is inadequate because dissolved water cannot be centrifuged out. And the spec dictates total water of 500ppm. So if you've already got free water without even testing, it's virtually certain it's not ASTM as the bio is probably already partially saturated. If you think there are still points of disagreement, why don't you just say what you mean instead of trying to set semantic traps.

[Diesel Addict]

Originally Posted by TomB

Were they trying to sell you a solution for this "issue?" Could have been good ol' salesmanship of creating a need for a product they sell.

What solution would that be?

[Diesel Addict]

Originally Posted by TomB

That was the intent of the original post.

Scare you off of BD even though REAL life experience proves this does not happen.

Speak for yourself. Do I really sound like I'm trying to scare people away from BD?? That was certainly not my intention. If anything I encourage the use of alternative energy. I also encourage being informed and knowing the risks and not just the benefits.

[Diesel Addict]

Originally Posted by UFO

It sounds like semantics to me. Do you dispute the spec is 500ppm? Do you dispute the spec is separate from the testing method? Obviously the spec is inadequate because dissolved water cannot be centrifuged out. And the spec dictates total water of 500ppm. So if you've already got free water without even testing, it's virtually certain it's not ASTM as the bio is probably already partially saturated. If you think there are still points of disagreement, why don't you just say what you mean instead of trying to set semantic traps.

All I know is that b4black's posts are a lot more coherent than yours. You just love to argue, don't you?

[tdileadfoot]

Originally Posted by HoneyBeetle

You say biodiesel is an additive. I thought it was a subsitute or alternative for regulator diesel.

Most Biodiesel sold at the pump is ULSD with B100 added (B5 = 5% B100)

IF you go to the link I posted you will see test results that prove when B100 is added to ULSD at a ratio of 2% (B2) lubricity improved significantly.

Using B100 as an additive (2% B100) results in less wear on fuel system components such as Injector pumps.

B100 used as an fuel lubricity additive was more effective than all other diesel fuel additives tested.

This is the reason I would want to blend B100 in my fuel tank while refueling with ULSD.

I would fill up with B5 if I could find it. B5 is just not available in the Pittsburgh area. The one station that sold B5 is closed.

[tdileadfoot]

Originally Posted by HoneyBeetle

"I haven't heard much discussion of the value or benefits of mixing or using bio-fuel by any mixing methods (e.g., fill up once in a while, pre-mix or use small quantities per tank of fuel). What would the benefits be and can you put a value on them? Also, what are the bad points, i.e., detriments?

So, my "take-away" based on this thread is that there "might" be a benefit to mixing bio-diesel with regular diesel which could be, lubricity. However, this is assumed. I"m not sure if it is so. So, does water in the fuel actually "outweigh" any alleged lubricity benefit? Is this what you are saying?

Never the less, based on my reading of this "scholarly" conversation, there are no posts on #1, if mixing is really a benefit and what are the benefits, #2, whether or not mixing would work for my TDI in my region and why.

I guess you guys are simply talking about "methods" of mixing, which is best and why.

My CTSs are whether or not this is a good thing to do or not. If it isn't, there would be no need to speculate on the mixing methods. I've read threads on bio-diesel, but I can't seem to get a good concensus of what is good for your TDI and why. I a few blurbs of opinion, but no solid data or verifyable info."



The link below contains solid data and is verifyable.

Reduced fuel component wear is a benefit I can put a value on.

http://www.dieselplace.com/forum/sho...d.php?t=177728

[HoneyBeetle]

Thanks. I appreciate the info. Carry on....lol!

Originally Posted by anahata

HB,
There are many places to research 'occasional' use of B-100 here and much has been written. I am far from a guru but am an avid reader of the forums. My understanding is that good B-100 is a great fuel but seals on (edit) injector pumps on cars old enough to have run on regular LSD are prone to failure when switching between fuels - because the different fuels contain different aromatics and/or aniline which variously swell or shrink the seals stressing them when fuels are substantially changed.
I haven't seen a decisive conclusion as to whether or not it is 'safe' to go from one extreme to another with IP seals that have only seen ULSD and Biodiesel. My seals ran all three fuels and eventually leaked. So, it will not harm the engine but the IP seals could be another story.

http://forums.tdiclub.com/search.php?searchid=4320890
http://forums.tdiclub.com/showthread.php?t=157540

I would pick a blend and stick with that blend myself even after having new seals put on the pump and only running ULSD. It is said that IP's with seals that have only pumped ULSD are less vulnerable but I don't want to take that chance. I too am interested in any further light on this though I don't want to divert this thread.

Back to topic...FWIW I live in Arizona and have been splash blending to equivalent of B-5 for 4 years (it's cheaper! AZ petro sells B5, B20 & B99 but am not sure how they blend it) I too was under the impression that Biodiesel is MORE dense and not less dense than Dino. This would be a major decider in which fuel to add first if one is splash blending. Any conclusive answers about the relative density question?

[CsTDI]

couple of points:

WATER: -Most BD and D2 stations should be dispensing these fuels after running them through pump filters that include water separation. So you have the manufacturer producing it hopefully to spec., additionally the station filters for water, and then the vehicle also separates for water. That is a lot of checks and if your experience is like mine i.e the vehicle's fuel filter is free of water, I am not concerned about water separating out and would think the vehicle is moving fuel as designed

-if splashing blending is not truly blending, over long term, you should eventually end up with a full tank of B100. I do not think anyone has experienced this. However, without knowing the quality of every fuel (or blend) out there and knowing that poor quality (out of spec) fuel posts definitely pop up every now and then (some do find water in the vehicle fuel filter separater, and I am sure that I have filled at stations that were pumping without filter in the past), I would think that you need to make sure that you are prepared especially in the winter months to deal with blends that are not mixing/mixing well and the resultant problems.

In terms of the frequency of using BD. Assuming that BD is splash blending well, BD only provides its benefits when being stored and injected through the vehicle. To use it say once every few months, limits its benefits to once every few months. I would say your vehicle and you would reap more benefits with the same quanity of BD portioned over every tank (assuming at least B2) then just once in awhile. Of course, if it is not blending well, then adding BD once every several tanks would have yielded the best result. But again, I have read of noone posting a find of B100 in the tank caused by stratification

[dieselfuel]

I've been adding 1 quart of commercial BD to about 8 gals when I fill up. I've been doing this for about 4 months now.

One cold evening (35F) I set a quart of the BD outside overnight, and it looked the same as when room temp. : No cloudiness.

I've got to believe splash-filling is fine. I drive 16 mi one way to get my D2.

So, 16 mi. drive home on the interstate, and stop and go through the city, I think mixes the fuels just fine.

Not to mention all the hard breaking and hard left and right turns! :>)

The first tank I mixed was in September and was about a B60 mix. My 2003 ALH ran great.

So far, my filter hasn't clogged (about 6000 miles).

df

[Austinatlanta]

I am adding 1 gal of B20 for every three gal of regular diesel fuel for the lubrication increase that it gives. I wait until I have 1/4 tank left before refueling and the good news is that I live right next door to the biodiesel fueling station. The bad news that the diesel station that is used frequently,( i.e is by a major hwy), is 10 miles away. Does it matter if I put in a couple of gal of B20 when the tank gets to 1/4 a tank and then drive the 10 miles to the diesel station? Or should I put the B20 in after the regular diesel fuel? Does driving the 10 miles on 1/4 tank with 2 gals of B20 cause the issues described with using greater than 5% bio in the CR engines for that short distance?

[tdileadfoot]

Originally Posted by Austinatlanta

I am adding 1 gal of B20 for every three gal of regular diesel fuel for the lubrication increase that it gives. I wait until I have 1/4 tank left before refueling and the good news is that I live right next door to the biodiesel fueling station. The bad news that the diesel station that is used frequently,( i.e is by a major hwy), is 10 miles away. Does it matter if I put in a couple of gal of B20 when the tank gets to 1/4 a tank and then drive the 10 miles to the diesel station? Or should I put the B20 in after the regular diesel fuel? Does driving the 10 miles on 1/4 tank with 2 gals of B20 cause the issues described with using greater than 5% bio in the CR engines for that short distance?

Biodiesel is slightly heavier than diesel fuel. It might be better to "splash" the B20 on top of the diesel. Or you could load the Biodiesel on top of 1/2 tank. then fill up. That way you could end with a full tank. Also 32oz of B100 on top of 4.75 gallons is B5. If B100 is available you could mix B5 in 5gal containers and then splash that on top of 1/2 tank This would come close to B2. B2 will greatly improve lubricity. "Splashing" B5 on top of 1/2 tank should not cause any issues that have been discussed here. The 5gal can gives you a chance to "blend" the bio to B5 first.