[eurojulien]

I'm sure this has been covered somewhere but a search didn't bring it up.

I know the factory allows for 7% BIO which is what I've started doing (fill ~2 gallons with b50). I was thinking of maybe going to b20 as time went on but I have read that the post injection cycle (for the dpf regen) can cause issues if you run high quantities of biodiesel in our cars. Does anyone have any information on this?

Also, if I were to pick up a downpipe and the appropriate tune for it, would it be ok to run higher concentrations of bio (b50-b99?)

I live in a market with many pumps that carry quality bio, so it'd be nice to know what I can safely run. I used to run b99 in my alh and b20 in my pd vws.

[TDIwyse]

Originally Posted by eurojulien

I'm sure this has been covered somewhere but a search didn't bring it up.

I know the factory allows for 5% BIO which is what I've started doing (fill ~2 gallons with b50). I was thinking of maybe going to b20 as time went on but I have read that the post injection cycle (for the dpf regen) can cause issues if you run high quantities of biodiesel in our cars. Does anyone have any information on this?

Also, if I were to pick up a downpipe and the appropriate tune for it, would it be ok to run higher concentrations of bio (b50-b99?)

I live in a market with many pumps that carry quality bio, so it'd be nice to know what I can safely run. I used to run b99 in my alh and b20 in my pd vws.

You're likely to get a wide range of feedback on this question.

One sample point: The Sinclair truck stop nearest me that I usually fill up at has been carrying ULSD with 5-20% Biodiesel (they won't say exactly how much it is at any given point, just that it's between there) for the last ~4-5 years. Basically as long as I've had this car. Have used this fuel in all my diesel vehicles and garden tractor and generator... The first 3 yrs of the 335d it had the DPF. I did multiple used oil analysis on the vehicle and never had any fuel dilution issues.

However, I can't say with any degree of certainty exactly how much biodiesel I was using ... except that it's been at least 5% and not more than 20% ...

[BB_cuda]

sorry, what is alh? I have similar question as well and I am down piped now. I can get B99 downtown. Here is something to consider though. I have read there are certain things that form from running petrodiesel that of course petrodiesel doesn't dissolve. These compounds are dissolved by biodiesel. Seems I've read elsewhere that going immediately to pure bio has spelled trouble in terms of dissolving the stuff and it reforming elsewhere in fuel system and clogging stuff up. The lesson learned I recall is to ramp up in concentration slowly or run high concentration of bio very early on.

I've heard people here be either very negative of biodiesel or very positive. Doesn't B99 have a cetane of like 56 points? It is supposed to be muy bueno for injection pumps and has superior performance in the wear scar test. I hope i'm not starting another debate on wear scar testing, need to worry, don't need to worry, yada yad yada.

Let's focus on OP's question. I'm just about to run out of warranty so the B7 limit (that what my fuel cap says, 2011 model year) is about to no longer matter.

Pump i visit has always been marked "up to" 5% biodiesel so I have no clue if i have been running B0, B2, or the potential full B5. I have often thought of doing what OP is and going downtown and getting the pure stuff and using it as an additive to keep HP pump happy and boost cetane along the way. B20 was what i was pondering but don't know what I'm mixing with (B0 or B5?).

[eurojulien]

Originally Posted by BB_cuda

sorry, what is alh? I have similar question as well and I am down piped now. I can get B99 downtown. Here is something to consider though. I have read there are certain things that form from running petrodiesel that of course petrodiesel doesn't dissolve. These compounds are dissolved by biodiesel. Seems I've read elsewhere that going immediately to pure bio has spelled trouble in terms of dissolving the stuff and it reforming elsewhere in fuel system and clogging stuff up. The lesson learned I recall is to ramp up in concentration slowly or run high concentration of bio very early on.

I've heard people here be either very negative of biodiesel or very positive. Doesn't B99 have a cetane of like 56 points? It is supposed to be muy bueno for injection pumps and has superior performance in the wear scar test. I hope i'm not starting another debate on wear scar testing, need to worry, don't need to worry, yada yad yada.

Let's focus on OP's question. I'm just about to run out of warranty so the B7 limit (that what my fuel cap says, 2011 model year) is about to no longer matter.

Pump i visit has always been marked "up to" 5% biodiesel so I have no clue if i have been running B0, B2, or the potential full B5. I have often thought of doing what OP is and going downtown and getting the pure stuff and using it as an additive to keep HP pump happy and boost cetane along the way. B20 was what i was pondering but don't know what I'm mixing with (B0 or B5?).

ALH is the motor used in Volkswagen TDI from 99.5-2003. Its a basic variant of the rotary pump turbo diesel motor that they've been running for years but with a variable vane turbo. These can run b99 bio all day long, if the outside weather doesn't drop below the 40s. The PD is the successor of the ALH which uses individual "pump" style injectors that are ran by the camshaft. Since the camshaft is put under considerable load from these pump injectors it was mentioned on tdiclub that the increased viscosity of bio could ramp up the injection pressure too high and cause issues. No hard data though about failures.

Bio does have a higher cetane rating than D2, but it does carry less BTUs of energy. So less smoke and less power.

[kiel_dafo_kenyg_as]

I wouldn't pump this crap even it was for free

[gtp900]

Originally Posted by eurojulien

Bio does have a higher cetane rating than D2, but it does carry less BTUs of energy. So less smoke and less power.

Higher cetane= better burn= better performance/more power, so even if other fuels have more btu's, if your not burning all of it your just wasting it anyway.
What is the btu content difference?

[eurojulien]

Originally Posted by gtp900

Higher cetane= better burn= better performance/more power, so even if other fuels have more btu's, if your not burning all of it your just wasting it anyway.
What is the btu content difference?

Here is a good comparison between bio and d2:
http://www.extension.iastate.edu/agdm/wholefarm/html/c6-87.html
Admittedly the delta in btus is less than I thought.

About cetane, yes bio burns better but since diesel motors don't rely on stoic you can just cram a bunch more d2 until you have fulfilled your fueling needs. As evidenced by many a douchebag pickup owner.

[TDIwyse]

This was an interesting data point. Comparison on D2, B5, B100 and (gasp) vegetable oil, done on the same direct injected turbo diesel car (VW TDI ... pre-common rail version).

http://www.consumerreports.org/cro/2012/05/diesel-vs-biodiesel-vs-vegetable-oil/index.htm


Thought the mpg, acceleration and 1/4 mile speed comparisons were interesting.

[eurojulien]

Originally Posted by TDIwyse

This was an interesting data point. Comparison on D2, B5, B100 and (gasp) vegetable oil, done on the same direct injected turbo diesel car (VW TDI ... pre-common rail version).

http://www.consumerreports.org/cro/2012/05/diesel-vs-biodiesel-vs-vegetable-oil/index.htm


Thought the mpg, acceleration and 1/4 mile speed comparisons were interesting.

yeah, that is really interesting. I guess somewhere around b5 is the best of both worlds

[BB_cuda]

My minor problem is i don't know if i really get the B5 at the pump as it says "up to". It could be regular B0. Maybe the safe play is to add enough B100 to get a B5 mix assuming I'm pumping B0 at station. If the Station really has B5 then perhaps I would really be running B10 then. I want to lube the injection pump is my motivation. Its either this or Optilube XPD.

[Mik325tds]

About 10 years ago, rapeseed oil was quite cheap in Germany and I ran a 50% mix with regular diesel in my 325tds for quite a while. No issues. But that car had a distributor pump and people said to not use it in common rail diesels because it could cause too high pressure.
One of my colleages got into picking up used frying oil from restaurants, filtering it and runnning it in his old MB 190D.
Anyway, the smell was quite bad and studies came out saying that the emissions of rapeseed oil would increase cancerous lung diseases by 10-30%. Interesting that the CR test doesn't mention anything about that.

[eurojulien]

Originally Posted by Mik325tds

About 10 years ago, rapeseed oil was quite cheap in Germany and I ran a 50% mix with regular diesel in my 325tds for quite a while. No issues. But that car had a distributor pump and people said to not use it in common rail diesels because it could cause too high pressure.
One of my colleages got into picking up used frying oil from restaurants, filtering it and runnning it in his old MB 190D.
Anyway, the smell was quite bad and studies came out saying that the emissions of rapeseed oil would increase cancerous lung diseases by 10-30%. Interesting that the CR test doesn't mention anything about that.

I *think* that is when applied to an un-catalyzed car running WVO, *perhaps* because of atomization issues.


This little guy was once filled up at ALDI with colza oil, and 1L of the finest cooking oil because my uncle hated it and settled the argument with his significant other by sticking it in my tank

[bkhi]

I have 25,000 miles on my 2011 335d, all on B100. I do mostly city driving, which is bad, and I do get oil dilution. I just change the oil more often. Everything else has been fine. I had a NOx sensor go out and the dealer replaced it under warranty. They determined it was not biodiesel related. Very happy with my experience, and just picked up a 2011 X5d, which I'll also run on B100. BTW - the X5 had a NOx sensor failure code when I purchased it, and had never had biodiesel in the tank. I caution to use ONLY on spec biodiesel, not vegetable oil.

[koreez88]

I occasionally fill the car up with B20 (I'd say every 4th pump). Had the car for over 4 years and so far so good.

[eurojulien]

Originally Posted by bkhi

I have 25,000 miles on my 2011 335d, all on B100. I do mostly city driving, which is bad, and I do get oil dilution. I just change the oil more often. Everything else has been fine. I had a NOx sensor go out and the dealer replaced it under warranty. They determined it was not biodiesel related. Very happy with my experience, and just picked up a 2011 X5d, which I'll also run on B100. BTW - the X5 had a NOx sensor failure code when I purchased it, and had never had biodiesel in the tank. I caution to use ONLY on spec biodiesel, not vegetable oil.

If you don't mind me asking, what oil change intervals are you running? How much oil dilution are you getting?

Thanks

[Thisonegoestoeleven]

Apparently in Oregon, all stations use at least b5. One station near home has b20. I'm looking into figure out if this would cause any issues for my car. Changing a fuel filter or engine oil more frequently doesn't seem like too bad a trade off.

[floydarogers]

Originally Posted by Thisonegoestoeleven

Apparently in Oregon, all stations use at least b5. One station near home has b20. I'm looking into figure out if this would cause any issues for my car. Changing a fuel filter or engine oil more frequently doesn't seem like too bad a trade off.

BMW (and others) accept up to B7. Many people "get" to run B5, and there are no adverse affects - oil reports show little or no oil dilution, and the fuel filters don't care.

[Thisonegoestoeleven]

I guess it's the b20 that I'm worried about. I'm not finding much conclusive data on the matter.

[BB_cuda]

Diesel pumps in Texas are marked "up to 5% biodiesel". We don't know if this means it varies from load to load for a given station OR if varying stations have B0 to B5 content.

Is there a way to have diesel tested by a consumer for Bx content? One would think that since i live in one of the petrochemical meccas, it could be done here if anywhere.