# Biodiesel content and your warranty



## finnbmw (Jul 6, 2008)

My apologies if this has been discussed prior, but I saw this interesting article http://www.thedieseldriver.com/2012/10/biodiesel-report-what-b20-means-to-you-and-your-warranty/


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## KeithS (Dec 30, 2001)

Article is a bit misleading in their example of the Mercedes owner where they said:

"Several months ago, the Illinois-based owner of a 2009 Mercedes-Benz R350 BlueTec reported a two thousand dollar repair bill to ***8220;clean the engine and intake manifold from the residue left over from using B20 diesel fuel for 90K miles,***8221; pointing out that this is ***8220;the only diesel fuel available in the state of Illinois!***8221;

From the knowledge gained from this board and others, I'm pretty sure that the B20 had nothing to do with the "residue" which we call carbon buildup. I'm not suggesting everyone go out and start using B20 either. Bottom line is we really have little control over the bio content of the fuel we are using.


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## TDIwyse (Sep 17, 2010)

Thanks for posting that.

There are pros and cons with all fuels. It's good to learn the tradeoffs of what you put in your property. However, I noticed a lot of things in there that are incorrect or speculations portrayed as facts. Speculations without science to test the claims are a pet peeve of mine.

In an attempt to try to give some balance on this let's consider a few examples to follow.

The very first sentence is factually incorrect.

_Five years ago, biodiesel was a form of fuel that the diesel enthusiast would convert his or her vehicle to use. _

5 years? Uhm, no. "Converting" the vehicle to use it? No. Biodiesel has been around a lot longer than that. I was buying it commercially ~15 yrs ago.

http://www.biodiesel.com/index.php/biodiesel/history_of_biodiesel_fuel

This following claim is funny to me.

_Several months ago, the Illinois-based owner of a 2009 Mercedes-Benz R350 BlueTec reported a two thousand dollar repair bill to "clean the engine and intake manifold from the residue left over from using B20 diesel fuel for 90K miles," pointing out that this is "the only diesel fuel available in the state of Illinois!"_

Direct injected engines utilizing EGR have intake manifold clogging issues, both gasoline and diesel variants. It's the unfortunate nature of emission control schemes. We've seen this in the VW TDI community for many years on vehicles that haven't used biodiesel. We've seen this in the 335d community as well. We've seen it in the 335i community... and the list goes on.

And then there's issues in this paragraph as well:

_Modern diesel passenger cars currently being offered in the U.S. were designed to use B5, or 5% biodiesel content; as a consequence, using blends with as much as 20% biodiesel have caused problems ranging from check engine warnings to reduced fuel economy and outright engine failure. In addition, the manufacturers' warranties on these cars support the use of only up to B5, which was the biodiesel standard when the cars were engineered to meet U.S. and especially California Emissions standards. The move towards higher biodiesel content fuel has the unfortunate side effect of, putting the consumer on the hook for the cost of repairs which can be rather expensive._

The Chevy Cruze diesel, which has passed EPA official mileage ratings and going on sale, was designed to use and is warrantied for B20 use.

http://www.prnewswire.com/news-rele...ing-list-of-b20-ready-vehicles-190557151.html

Also, how has the author verified the cause of these problems is biodiesel related? People get the same problems with pure petroleum fuel. Trying to scientifically control all the variables to prove that statement would be a challenge. I'd like to see the science that supports the conclusion.

Also, no vehicle warranty covers damage from bad fuel. For example, There's all kinds of cases of people filling up at diesel pumps that actually had gas in it and caused engine damage. The warranty doesn't cover this, the fuel stations insurance would be the one to cover this.

There's other issues in there as well, but this should hopefully give some balance to what appears to me to be an alarmist article with a lot of unsubstantiated claims.

Oh, and the author fails to mention problems with US petro diesel. There's concerns over fuel lubricity. Our US fuel spec for lubricity is higher than Europe, and what fuel injection manufacturers want for the fuel pumps, which lowers the expected lifespan of the HPFP. So sticking with straight petro diesel has its problems too it is out of spec from a HPFP point of view...

http://www.globaldenso.com/en/topics/091012-01/documents/common_position_paper.pdf

_Lubricity: It is essential that the lubricity of the fuel as measured by the HFRR test specified in ISO 
12156-1 meets the requirement of a wear scar diameter not greater than 460 microns. In addition, it is 
recommended by the Diesel FIE manufacturers, that "first fill" of the fuel tank should be with fuel with 
good lubricity characteristics (HFRR < 400 µm) in order to guarantee good "run-in" of the injection system 
components. *The US diesel specification (ASTM D 975-09) includes a lubricity value of 520 µm maximum 
(according to ASTM D 6079). It is expected that the useful operating lifetime of any mechanical 
component will be adversely affected by fuel with a lubricity exceeding 460 microns*. _

And TDIclub has some links to random sampling VW did of fuel around the US as it struggled to contain the HPFP failures it was seeing with its new TDI's (and there's a federal investigation still going on of that) and an alarming number of samples had lubricity values above the already high 520um spec limit.

Pros and cons to all fuel choices...


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## Pierre Louis (Oct 23, 2011)

There are many possible causes of HPFP failures even though there are those that wish they could prove the lubricity argument. Although fuel pump manufacturers understandably push for better fuel lubricity, the HPFP data so far seems to fail to support this claim. A substantial percentage of fuel found was of good lubricity when HPFP failures occurred, while a good percentage of HPFP "failures" included no defects in the fuel pump at all. The most likely culprit seems to be gasoline contamination in the tank when the HPFP failure occurs, but this does not explain it all.

PL


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## TDIwyse (Sep 17, 2010)

Pierre Louis said:


> There are many possible causes of HPFP failures even though there are those that wish they could prove the lubricity argument. Although fuel pump manufacturers understandably push for better fuel lubricity, the HPFP data so far seems to fail to support this claim.


I'm sorry, but that's just not backed up by the science.

http://www.arb.ca.gov/fuels/gasoline/meeting/2003/022003bosch.pdf

Page 12 shows a quantifiable analysis on life expectancy of the HPFP vs lubricity. Lower lubricity quantifiably, measurably and verifiably reduces the life of the pump. To say otherwise is simply ignoring reality. And there's a dramatic and sharp reduction in life above 450um. One tank of really low lubricity fuel can significantly impact the lifespan.



Pierre Louis said:


> A substantial percentage of fuel found was of good lubricity when HPFP failures occurred, while a good percentage of HPFP "failures" included no defects in the fuel pump at all. The most likely culprit seems to be gasoline contamination in the tank when the HPFP failure occurs, but this does not explain it all.
> 
> PL


Just because the particular fuel in the tank at the time the car had a HPFP failure may have had acceptable lubricity tells us nothing about the fuel that was used in it previously. It's a long term, statistical failure cause, and relying on what's in the tank at the moment as a basis to conclude what it had in there previously is, well, poor failure analysis. That would be like concluding that an obese man who has a heart attack while exercising with a stomach full of a salad had been practicing good dietary and exercise habits for the preceding years of his life (when he could have been a smoking, over eating coach potato).


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## TDIwyse (Sep 17, 2010)

Some of the official background data as an FYI for those who may not be familiar.

http://www-odi.nhtsa.dot.gov/acms/cs/jaxrs/download/doc/UCM430237/INRL-EA11003-54326P.pdf

From pg 30 (lots of out of spec fuel out there that can reduce the life of the HPFP).

_827 diesel fuel samples have been acquired throughout the continental U.S. 
In respect to viscosity, 203 samples were out of ASTM specification (below 1.9 cSt), 186 
of those were below the HPFP's nominal threshold of 1.5 cSt. Here the HPFP may not 
have been properly lubricated. 
59 samples were detected with lower lubricity (greater HFRR/WSD value) than required. 
22 of them exceeded the HPFP's nominal tolerance of 570µm and may have caused 
increased wear. 
4 samples were found to contain increased amounts of water more than 1.5 % / 1.8% / 
2.5 % and one sample exceeding 10% of water, which was not detected in the fuel 
station and random vehicle surveys. Viscosity and lubricity are within specification, but 
water could cause rust and corrosion in the HPFP and damage the pump. 
79 samples contained more than 5% biodiesel, 20 of those exceeded 10%. Biodiesel 
itself does not damage the HPFP, however, collapsed/deteriorated/aged biodiesel can 
cause deposits inside the HPFP and clog filters, interrupting the lubrication and leading 
to failure. 
252 samples showed a flashpoint below ASTM specification, but this has no direct 
impact to the HPFP's durability and may just be seen as an indicator for possible 
gasoline content. _


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## F32Fleet (Jul 14, 2010)

TDIwyse said:


> Some of the official background data as an FYI for those who may not be familiar.
> 
> http://www-odi.nhtsa.dot.gov/acms/cs/jaxrs/download/doc/UCM430237/INRL-EA11003-54326P.pdf
> 
> ...


So 7% had wear scar over 520 but less than the max (570) allowed by the HPFP Manufacturer and of on 2.6% had wear scar which exceeded manufacturer specs.

Not seeing a lubricity issue with regards to these VW HPFP failures.

The Fuel Injection Manufacturer are just playing CYA. Their statement is purposely vague.


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## d geek (Nov 26, 2008)

TDIwyse said:


> ...Just because the particular fuel in the tank at the time the car had a HPFP failure may have had acceptable lubricity tells us nothing about the fuel that was used in it previously. It's a long term, statistical failure cause, and relying on what's in the tank at the moment as a basis to conclude what it had in there previously is, well, poor failure analysis...


I concur, and agree with ensuring the fuel has adequate lubricity (<460 micron wear scar), but until VW provides actual data on failed components we are still in the dark as to how these failures are occurring.


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## TDIwyse (Sep 17, 2010)

BMWTurboDzl said:


> So 7% had wear scar over 520 but less than the max (570) allowed by the HPFP Manufacturer and of on 2.6% had wear scar which exceeded manufacturer specs.
> 
> Not seeing a lubricity issue with regards to these VW HPFP failures.
> 
> The Fuel Injection Manufacturer are just playing CYA. Their statement is purposely vague.


203/827 = 24.5% fuel samples out of spec for viscosity, which will shorten HPFP life.
59/827 = 7.1% fuel samples out of US minimum spec for lubricity, which will shorten HPFP life. (The 570 level is where dramatic decrease in life happens, not what is "allowed by the HPFP Manufacturer". Even 520 shortens the life of the HPFP over the manufacturer's recommended 460 level)

The measured data on HPFP life has been measured by Bosch for their HPFP's. Lifespan is dramatically lowered by out of spec fuel. This is hardly a CYA. Their measured data on lifespan is not vague. It is quantifiable, measurable and reproducible.


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## TDIwyse (Sep 17, 2010)

d geek said:


> I concur, and agree with ensuring the fuel has adequate lubricity (<460 micron wear scar), but until VW provides actual data on failed components we are still in the dark as to how these failures are occurring.


I agree, there seems to be more than lubricity involved with VW's issue. This is demonstrated by the multiple revisions of that pump.

My point was that lubricity is a known, measurable failure mechanism for HPFP's, and the US petro diesel spec is higher than recommended by those manufacturers.


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## finnbmw (Jul 6, 2008)

Interesting discussion. Question to the experts: What should we do to keep our BMW's running a long time without HPFP/injector problems?

Additives? BMW does not recommend using any.
Biodiesel? BMW only approves up to 5%

Seems like we are in a Catch-22 situation and at the mercy of the fuel suppliers. I've been using 95%+ Chevron fuel as I read somewhere that their diesel is among the best. Who knows? :dunno: Remember that here in Southeast, we do not have premium diesel (at least haven't seen any), so probably the cetane numbers even from Top Tier stations are closer to 40 than 50.


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## rmorin49 (Jan 7, 2007)

What agency(ies) monitor the quality of biodiesel? Is it done at the state level? I know in MD the state licenses and registers gas stations and pumps but who checks the quality of the fuel itself. I think much of it comes from out of state and is trucked in from storage depots in VA and PA.


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## d geek (Nov 26, 2008)

rmorin49 said:


> What agency(ies) monitor the quality of biodiesel? Is it done at the state level? ...


fuel quality is monitored and enforced at the state level


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## d geek (Nov 26, 2008)

Who here is concerned that the HPFP used in the 328d is the same Bosch design used in the VW common rail engines?


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## rmorin49 (Jan 7, 2007)

During my diesel ownership I noted that many of the diesel pumps did not have the brand name of the fuel on them. At Exxon stations it was usually at a different location and was unbranded. I asked about it and the attendant says that most of the diesel sold in my area all came from the same place. True?


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## d geek (Nov 26, 2008)

there are exceptions but generally this is true to the extent that one distribution terminal serves many retailers. The additives are mixed in when the truck is filled at the terminal. That's where the main difference lies.


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## Pierre Louis (Oct 23, 2011)

TDIwyse said:


> I'm sorry, but that's just not backed up by the science.
> 
> http://www.arb.ca.gov/fuels/gasoline/meeting/2003/022003bosch.pdf
> 
> ...


Yes, the so-called "science" uses US diesel fuel data from 2002 before the ULSD standard came in which by itself was a large improvement in fuel lubricity and uniformity. It doesn't explain why only one pump model has most of the problems and why there are inconsistent reports of fuel lubricity relating to fuel pump "failures."

Most of the lubricity argument goes by what Bosch presented before ASTM standards were changed and the "rub" is the difference in lubricity number, something that has not been adequately shown to make a difference in the real world where fuel quality may actually be better. Its not that any critical scientific analysis wouldn't go by what they say to some extent, its that field experience needs to mirror lab data before we can jump to conclusions that don't really explain what is really happening.

The obese thing is a great example, since for years researchers believed obesity leads to heart disease but couldn't find any proof at all and still can't unlink obesity from the real risk factors of diabetes, hypertension, high cholesterol, sedentary lifestyle etc where obesity is only an aggravating factor, not a major one.

There is so much bias in all research that once we believe something, we look for it no matter what. It also explains why so many people still take Vitamin C for colds when basically all the studies show no effect except one or two where it was trivial.

PL


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## Pierre Louis (Oct 23, 2011)

d geek said:


> there are exceptions but generally this is true to the extent that one distribution terminal serves many retailers. The additives are mixed in when the truck is filled at the terminal. That's where the main difference lies.


In other words, you get the additives that the brand name, say Chevron/Texaco, has. Unbranded fuel is likely to have unbranded (read: inferior) additive.

Apparently not every brand name station has branded diesel, however, so its a bit tricky.

PL


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## TDIwyse (Sep 17, 2010)

Pierre Louis said:


> In other words, you get the additives that the brand name, say Chevron/Texaco, has. Unbranded fuel is likely to have unbranded (read: inferior) additive.
> 
> Apparently not every brand name station has branded diesel, however, so its a bit tricky.
> 
> PL


This assumes they remember to put the additive package into the truck after its loaded at the terminal...


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## TDIwyse (Sep 17, 2010)

Pierre Louis said:


> Yes, the so-called "science" uses US diesel fuel data from 2002 before the ULSD standard came in which by itself was a large improvement in fuel lubricity and uniformity.


The study shows a clear connection with the variable they controlled: Lubricity. That's how a scientific study works, you control variables and test the theory you have and look to see if the measured data fit the theory. Lubricity has a direct, measurable impact to fuel pump life.

There's nothing magic about the differences of LSD instead of ULSD. The main spec difference is sulfur... Are you saying if Bosch used ULSD vs LSD in the lubricity study there would be a different result?

And I would have to take exception to the claim that ULSD standard has had a "large improvement in fuel lubricity and uniformity". VW's data sampling of fuel outlets shows horrible uniformity with large percentages of fuel being out of spec...



Pierre Louis said:


> It doesn't explain why only one pump model has most of the problems and why there are inconsistent reports of fuel lubricity relating to fuel pump "failures."


I agree the pump by itself has had some issues and its design increases loading on a smaller surface area ... This is one reason I stayed away from the VW and went with the 335d, as it uses the older, more robust HPFP.



Pierre Louis said:


> Most of the lubricity argument goes by what Bosch presented before ASTM standards were changed and the "rub" is the difference in lubricity number, something that has not been adequately shown to make a difference in the real world where fuel quality may actually be better. Its not that any critical scientific analysis wouldn't go by what they say to some extent, its that field experience needs to mirror lab data before we can jump to conclusions that don't really explain what is really happening.


The real world sampling of ULSD fuel in the US shows an alarming number of out of spec fuel that has direct, measurable impact to HPFP life (viscosity and lubricity as well as gas/water contamination).

Also, there is some good real world correlation that shows issues a connection with lubricity. Some great insight in this section of the massive TDIclub thread on the VW issues:

http://forums.tdiclub.com/showpost.php?p=4028053&postcount=4682

Not the increased failure rates occuring during the end of the warmer months. Warm fuel has less viscosity and lower lubricity with increases wear on the pumps ... and increased failures rates occur.

Also note that the statistical slant to the higher percentage of failures occuring in southern states where fuel temps would be hotter.

http://pics.tdiclub.com/showphoto.php?photo=92733&title=hpfp-failures-by-state&cat=5765



Pierre Louis said:


> The obese thing is a great example, since for years researchers believed obesity leads to heart disease but couldn't find any proof at all and still can't unlink obesity from the real risk factors of diabetes, hypertension, high cholesterol, sedentary lifestyle etc where obesity is only an aggravating factor, not a major one.
> 
> There is so much bias in all research that once we believe something, we look for it no matter what. It also explains why so many people still take Vitamin C for colds when basically all the studies show no effect except one or two where it was trivial.
> 
> PL


Don't forget the smoking in the risk factors  You can be overweight and healthy, I never said you couldn't.

But we are drifting way off topic here. The original discussion was regarding fuel (biodiesel above 5%) outside of the spec that some car manufacturers were designing too. I was pointing out that even petro diesel has problems, because the data proves an alarming number of petro diesel pumps using ULSD are also outside of the spec the manufacturers designed too.

There's pros and cons to all fuel you put in your car.


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## F32Fleet (Jul 14, 2010)

TDIwyse said:


> I agree, there seems to be more than lubricity involved with VW's issue. This is demonstrated by the multiple revisions of that pump.
> 
> My point was that lubricity is a known, measurable failure mechanism for HPFP's, and the US petro diesel spec is higher than recommended by those manufacturers.


My only gripe with the FIE statement is that they don't quantify what "Shortened lifespan" means. Does mean failure at 150k miles instead of 200k or 100k miles instead of 250k?

Is their statement simply an excuse for being unwilling to meet certain service life requirements? It's not like the lubricity requirement changed when we transitioned to ULSD.

Who knows.


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## KeithS (Dec 30, 2001)

d geek said:


> there are exceptions but generally this is true to the extent that one distribution terminal serves many retailers. The additives are mixed in when the truck is filled at the terminal. That's where the main difference lies.


This is definately true for gasoline, it is the additive that makes it a brand. But thought for diesel there were no branding additives, it is pumped as it came from the refinery?


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## F32Fleet (Jul 14, 2010)

KeithS said:


> This is definately true for gasoline, it is the additive that makes is a brand. But thought for diesel there were no branding additives, it is pumped as it came from the refinery?


Lubrizol is a big supplier of fuel additives. They even supply retail "Aftermarket", but won't tell you who.


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## TDIwyse (Sep 17, 2010)

BMWTurboDzl said:


> My only gripe with the FIE statement is that they don't quantify what "Shortened lifespan" means. Does mean failure at 150k miles instead of 200k or 100k miles instead of 250k?
> 
> Is their statement simply an excuse for being unwilling to meet certain service life requirements? It's not like the lubricity requirement changed when we transitioned to ULSD.
> 
> Who knows.


Well, it seems to me the Bosch study does quantify it. For example, page 11 has a table showing the wear scar ratings and durability reduction. At the higher end you get only 1% of the expected life and near "immediate failure". It also quantifies the failures that occurr with the different type of fuel pump designs along with photographs of what the failures look like. The "fretting" (http://en.wikipedia.org/wiki/Fretting) that occurs from lack of lubricity is the type of thing that would result in the metal particles that get strewn about the fuel system in those TDI failures.

Also, here's the official ASTM specs on diesel:

http://enterprise2.astm.org/DOWNLOAD/D975.101932-1.pdf

The only difference in spec for LSD vs ULSD that I can see is the sulphur rating.

However, the process for removing sulphur also strips some of the inherent lubricity from the fuel. Untreated LSD has inherent lubricity HFRR in the 390-500 range, where as ULSD is significantly higher at 600-800.

http://www.wellworthproducts.com/articles/lubricationsulfur.asp

If the load of ULSD misses its additive package then that load of fuel will have way out of spec lubricity.


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## Pierre Louis (Oct 23, 2011)

TDIwyse said:


> The study shows a clear connection with the variable they controlled: Lubricity. That's how a scientific study works, you control variables and test the theory you have and look to see if the measured data fit the theory. Lubricity has a direct, measurable impact to fuel pump life.
> 
> There's nothing magic about the differences of LSD instead of ULSD. The main spec difference is sulfur... Are you saying if Bosch used ULSD vs LSD in the lubricity study there would be a different result?
> 
> ...


Reading the actual ASTM decision on lubricity will tell you ULSD is much more uniform and has overall improvements in many aspects including lubricity over prior LSD.

Lab data is great and it is scientific, but science is about reality and theories to be believed must also be proven in the field. This is not so simple and has been an issue in many forums.

The information here is difficult to come by for many reasons. I am unaware of any statistics about total usage or incidence of problems etc. We don't know about how many fuel pumps go on without problems and for how many miles, for example. There is no "real world sampling of ULSD" data that is of any use either, probably due to real world variables not reproducible in the lab. You won't find proprietary data from aftermarket additive manufacturers using consumer fuel samples, for example, to support their claims published anywhere.

I enjoy the reasonable responses of most posters in the BMW world and have no axe to grind for or against any "theory" but lets not make believe there is science where it is not.

PL


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## d geek (Nov 26, 2008)

KeithS said:


> This is definately true for gasoline, it is the additive that makes it a brand. But thought for diesel there were no branding additives, it is pumped as it came from the refinery?


No- they can't put the additives in the fuel because the pipeline is used to transport various fuels and they are concerned that the additives will contaminate the pipeline. Therefore the additives are applied when loading the tanker truck that delivers to the retail outlet.

ULSD requires lubricity additives at a minimum. Others are mixed in to provide further benefits like increased cetane, water emulsion, etc.


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## F32Fleet (Jul 14, 2010)

TDIwyse said:


> Well, it seems to me the Bosch study does quantify it. For example, page 11 has a table showing the wear scar ratings and durability reduction. At the higher end you get only 1% of the expected life and near "immediate failure". It also quantifies the failures that occurr with the different type of fuel pump designs along with photographs of what the failures look like. The "fretting" (http://en.wikipedia.org/wiki/Fretting) that occurs from lack of lubricity is the type of thing that would result in the metal particles that get strewn about the fuel system in those TDI failures.
> 
> Also, here's the official ASTM specs on diesel:
> 
> ...


There is the issue I suppose. LSD could tolerate a half-ass treat rate whereas ULSD cannot.


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## TDIwyse (Sep 17, 2010)

I'm glad you don't have an axe to grind. Neither do I.



Pierre Louis said:


> Reading the actual ASTM decision on lubricity will tell you ULSD is much more uniform and has overall improvements in many aspects including lubricity over prior LSD.


I'd enjoy seeing a link to these ASTM decisions that shows ULSD has improved lubricity over LSD. The link I gave above shows exactly the opposite. I have a slew of other sources that show ULSD has much, much worse lubricity characteristics than the previous LSD.



Pierre Louis said:


> Lab data is great and it is scientific, but science is about reality and theories to be believed must also be proven in the field. This is not so simple and has been an issue in many forums.


The predictions Bosch and the other FIE manufacturers made are verified by field failures. There are other sources of failures (manufacturering defects for example where failures can occur even with on spec fuel), but there is a direct cause and effect relationship to HPFP lifespan and lubricity. To say otherwise is just incorrect...



Pierre Louis said:


> The information here is difficult to come by for many reasons. I am unaware of any statistics about total usage or incidence of problems etc. We don't know about how many fuel pumps go on without problems and for how many miles, for example. There is no "real world sampling of ULSD" data that is of any use either, probably due to real world variables not reproducible in the lab. You won't find proprietary data from aftermarket additive manufacturers using consumer fuel samples, for example, to support their claims published anywhere.


It appears you haven't thoroughly read and/or taken the time to fully comprehend the links from above, as they do address your comments ... usage statistics, failures by state as a % of total vehicles in that state, failure statistics by month, real world random samples of ULSD from sites across the US, etc. And all of this is available under the federal investigation at the NHTSA.

http://www-odi.nhtsa.dot.gov/acms/cs/documentList.xhtml?docId=EA11003&docType=INV

In addition, here's some independent analysis of lubricity affects with different additives. This study was not sponsored by any of the additive makers. And it's another source showing ULSD has an inherently bad lubricity in its untreated state (636 HFRR).

http://www.dieselplace.com/forum/76.../177728-lubricity-additive-study-results.html

Just 2% biodiesel took the 636 HFRR of the ULSD down to 221, which was by far the best result in the group.



Pierre Louis said:


> I enjoy the reasonable responses of most posters in the BMW world and have no axe to grind for or against any "theory" but lets not make believe there is science where it is not.
> PL


Please, show me quantifiable, measurable, testable data that validates your positions. I'd love to learn more on this subject. I've given a large amount of quantifiable, measurable, testable evidence to support my position, but it appears you aren't interested in absorbing it because it answered the objects you raised...


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## Pierre Louis (Oct 23, 2011)

TDIwyse said:


> I'd enjoy seeing a link to these ASTM decisions that shows ULSD has improved lubricity over LSD. The link I gave above shows exactly the opposite. I have a slew of other sources that show ULSD has much, much worse lubricity characteristics than the previous LSD.


 The links are probably old and/or need to have you pay to download them, but it is self-evident what went on at the ASTM meetings:

View attachment ASTM lubricity standard reference collection.pdf


PL


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## TDIwyse (Sep 17, 2010)

Thanks for posting that. It's always interesting to see how "design by committee" processes work.

_Citing several recent Society of Automotive Engineers papers, as well as Infineum's world-wide
diesel fuel survey, task force chair Nikanjam pointed out that North American diesel
equipment apparently isn't suffering failures from diesel fuels above 460 microns on HFRR.
One of the cited SAE studies shows that 550 microns is sufficient for the typical heavy-duty
diesel applications found in North America._

This was interesting, as it shows a focus on "heavy duty" diesel applications, which have different approaches to engines/fuel pumps then high speed automotive diesel engines (most of these applications have max rpm's at ~3000 or below, vs. the near 5000 rpm of high speed diesels). At that point in time the fuel pressures created by the fuel pumps were radically lower than modern common fuel systems. So it appears we are in agreement that on those older systems the level of lubricity was "adequate" for the fuel systems in place at that time.

This is a nice, short synopsis of the evolution of diesel fuel pumps over the years.

http://www.dieselpowermag.com/tech/1303dp_injection_system_basics/

Interestingly, it seems Infineum has evolved their position a bit since the paper you linked in regards to their take on lubricity.

http://www.infineum.com/Documents/Fuels Technical Papers/SAE/2009-01-0848.pdf

Some interesting things in there:

_Deep-desulphurization of diesel fuels leads to field failures of FIE when the fuel is not additive-treated [1,2].

Future applications - due to increased injection pressure requirements or transient conditions in current applications due to sliding conditions - could require further protection to ensure that the fuel injection system retains its integrity.

Conclusion 8. There is a good correlation between the HiTOM test, that uses real components of a Common Rail pump as test samples, and the HFRR. This suggests that the HFRR could successfully be used should the extra lubricity protection be required in the market place. _

But going back to VW and the CP4 version of the pump, which puts much more stress on its moving parts than the CP3, the present level of wear caused by our diesel fuel is causing a problem. Failure rates on that pump as a % of vehicles sold are worse in the US than Canada and Europe (where 460um is the spec), and the failure rate by month and on the map of the US shows the warmer the climate (which leads to lower viscosity and worse lubricity characteristics) and a statistically higher failure rate. All pointing to the fuel lubrication characteristics with this marginal pump design being a little on the low side.

As further evidence of fuel pump issues and temps &#8230; this is an interesting study (not done by any of the fuel injection pump manufacturers) about the impact of temp on low viscosity fuel and fuel injection pump life done by the military (they were trying to find ways to use a common fuel source to reduce logistics issues).

http://www.dtic.mil/dtic/tr/fulltext/u2/a284870.pdf

They concluded that in cold conditions, low viscosity and low lubricity fuels had acceptable field performance, but in more temperate environments rapid wear occurred and reliability was adversely affected . So this lines up with what is seen in the field with the VW CP4 failures (better lubricity specs in less warm conditions gives lower failure rates than the worse lubricity specs in warmer conditions).

Some pertinent conclusions of fuel with low lubricity relative to a given fuel pumps design limits. 
_7. Wear-related failures of rotary fuel injection pumps may be produced in a matter of hours with very low lubricity fuels such as neat Jet A-1 in a severe operating environment.
8. Laboratory wear tests indicate that the wear rate of Jet A-1 is reduced at low temperatures approaching the freezing point of water.
15. Wear with good lubricity fuels (BOCLE <0.62mm) appears to be independent of moisture content. The wear rate associated with poor lubricity fuels that produce a BOCLE wear scar diameter greater than approximately 0.62 is highly sensitive to the availability of moisture and the associated effects of temperature on water solubility._

Also, there's some good pics in this section of one of the many TDIclub threads on the CP4:

http://forums.tdiclub.com/showthread.php?t=284441&page=89

Lots of evidence of excessive wear on these pumps. Wear is strongly related to lubricity both in the field and in the lab.


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## Pierre Louis (Oct 23, 2011)

TDIwyse, a few positions by self-interested fuel pump manufacturers where what failure data there is points to misfueling, isn't enough. Its easy to just say its so without having the data to back it up: you must have a subset of cars driven with no misfueling at all that has measurable lubricity above 460 HFRR with a measurable failure rate and fuel pump metal scoring. This can be studied in fleet operations that use similar fuel pumps, such as the GM 2500's with CP4's, and get diesel from a single source. Funny thing, the Internet has few if any talk about fleet operators giving such data.

As for Canada and its lower HFRR number requirement, how do you know that Canadians just don't misfuel as much as those in the US? What is the misfueling rate in Europe?

How do you know from the limited data map of the US that the states that have higher "rates" of failure from the North don't have some other explanation when compared to states in the South with lower rates of failure? 

If Bosch is so concerned and correct, why shouldn't we expect mass HPFP failures from all the "inferior" US fuel very soon? Do you really think the likes of Chevron and Shell are sitting on their hands with all of this? Do you really buy the argument that HD big rigs, you know the ones that go a million miles on a CR turbodiesel pulling 100,000 lbs GVWR, even with their more expensive fuel pumps, don't need good lubricity?? Or isn't it now obvious Bosch and VW are looking to sell us cheap fuel pumps a la GM in the 1970's!!! I thought some older fuel pump designs are more susceptible to lubricity from some of the "guru's" on the Internet!

Of course future fuel pump designs with higher pressures will need to be more robust. At what cost and what failure rate will the best compromise occur? Certainly the VW/Bosch CP4.0 appears like it didn't cut it with even its low (1% per year?) but still-too-high failure rate, but our 335d CP3's seem to be doing fine, especially with their extra coated parts for North America and BMW's fuel nozzle restrictor in there from the beginning!

Sure, bad lubricity will cause pump failures. That's not the point. When in the field the plurality of pump failures are more likely from misfueling, one needs better statistics to show that lubricity improvement will make enough of a difference. 

The better question is what should the consumer look for when buying a new diesel and where should they look for engineering developments to go!? 

PL


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## subdude (Apr 11, 2013)

Could one conclude from Infineum 2009-01-0848 that it is advantageous to use a B5 blend if available(assuming a consistent high quality source)?


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## F32Fleet (Jul 14, 2010)

subdude said:


> Could one conclude from Infineum 2009-01-0848 that it is advantageous to use a B5 blend if available(assuming a consistent high quality source)?


Sure but not worth the trouble to actively look for it.


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## d geek (Nov 26, 2008)

D2 (normal diesel) can have up to 5% biodiesel with no additional labeling unless required in your particular state (like here in TX).


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## BB_cuda (Nov 8, 2011)

http://www.houstonbiodiesel.com/welcome

No hunting for it here in petrochemical mecca


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## TDIwyse (Sep 17, 2010)

subdude said:


> Could one conclude from Infineum 2009-01-0848 that it is advantageous to use a B5 blend if available(assuming a consistent high quality source)?


Yes. Even as little as ~1% does wonders to lubricity.


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## TDIwyse (Sep 17, 2010)

Pierre Louis said:


> TDIwyse, a few positions by self-interested fuel pump manufacturers where what failure data there is points to misfueling, isn't enough.


Who would know better than the people who designed the fuel pump what lubricity of fuel should be used in their product? This is so obvious I'm shocked people don't understand this. These "few positions by self-interested" manufacturer's (isn't it pretty much all of them?) are absolutely interested in their products working as they designed them to, because it impacts their bottom line &#8230; And Bosch designed the pumps in question to work with a 460 or better HFRR fuel. Worse lubricity directly shortens the pumps life in a measurable and predictable fashion. US has worse lubricity than other regions with many random samples (in the linked NHTSA reports) of fueling stations showing well above the already high spec level.



Pierre Louis said:


> Its easy to just say its so without having the data to back it up: you must have a subset of cars driven with no misfueling at all that has measurable lubricity above 460 HFRR with a measurable failure rate and fuel pump metal scoring. This can be studied in fleet operations that use similar fuel pumps, such as the GM 2500's with CP4's, and get diesel from a single source. Funny thing, the Internet has few if any talk about fleet operators giving such data.


There's lots of data already linked for you. The "say its so" is coming from the companies who designed the pumps. For fleet data, I linked the military study that has taken data on lubricity/viscosity impact to pump life in the lab and the field. And we have even better controlled data available than your recommendation &#8230; from the fuel pump manufacturers and the military study linked earlier. There is data of the pumps by themselves with specific fuels that have varying lubricity properties. No better isolation of this variable could be achievable in the field (although it does match field results as well). And the measured data shows precisely the direct wear and metal scoring that occurs, along with specific measurements of wear rates that is born out in the field.



Pierre Louis said:


> As for Canada and its lower HFRR number requirement, how do you know that Canadians just don't misfuel as much as those in the US? What is the misfueling rate in Europe?


I find it interesting how the previous VW diesels didn't have similar misfueling problems. Why would a CP4 fuel pump suddenly cause US drivers to put gas in their car? By the way, the data from NHTSA and the internal email exchanges between VW and Bosch (linked a few posts back) do not show higher misfueling rates. Some misfuelings, yes. But largely the fuel in the tanks at the time of failure were ok.

Haven't seen misfueling data from other places as the failure rates aren't as high and I don't think there's government agencies forcing VW to provide that data.



Pierre Louis said:


> How do you know from the limited data map of the US that the states that have higher "rates" of failure from the North don't have some other explanation when compared to states in the South with lower rates of failure?


It's not limited &#8230; its all the failures VW knew about at that time. And there are fuel samples that VW started taking from the tanks of many of the cars with failures. Their samples do not explain the differences in the rates of failure in warmer climates or the time of year the failures occur. What does explain it is the marginal fuel spec causes excess and accelerated wear in the warmer months/geogrphic areas. The warmer weather produces a statistically higher rate of failure, based on time of year and geographic location. Temperature impact and accelerated pump wear is noted in the military link I posted earlier. This unique failure profile of the VW pumps is explained by this&#8230;



Pierre Louis said:


> If Bosch is so concerned and correct, why shouldn't we expect mass HPFP failures from all the "inferior" US fuel very soon?


All fuel pumps will fail &#8230; some faster than others. Thanks to the fuel pump manufacturer testing there is data that shows excellent correlation of lifespan based on such specifications like lubricity. And the same failure mechanisms are also verified by other sources like the military analysis I linked earlier.

Thanks for using the "inferior" qualification. VW agrees with you. As you can see from one of VW's responses to the NHTSA regarding how concerned they and Bosch are over this issue. From the NHTSA documents:

_Volkswagen implemented design changes for the HPFP in May 2008, September 2009 and November 2010 to improve the robustness of the pump when used with *poor quality fuel*._

Note they call US fuel "poor quality" and that there's been 3 revisions on that pump on the VW to deal with "poor quality fuel".



Pierre Louis said:


> Do you really think the likes of Chevron and Shell are sitting on their hands with all of this?


As long as they meet the spec (which by the way, allows the HFRR to test at 560um due to the +/-40um accuracy of the test ... which means you could have 600um HRFF fuel going into your tank that still "passes spec") I don't think they care. They're following the rules they helped set. The biggest volume of their profit comes from heavy duty equipment, not fuel efficient modern diesel automobiles.



Pierre Louis said:


> Do you really buy the argument that HD big rigs, you know the ones that go a million miles on a CR turbodiesel pulling 100,000 lbs GVWR, even with their more expensive fuel pumps, don't need good lubricity?? Or isn't it now obvious Bosch and VW are looking to sell us cheap fuel pumps a la GM in the 1970's!!! I thought some older fuel pump designs are more susceptible to lubricity from some of the "guru's" on the Internet!


Semi tractor trailers absolutely have more robust systems on them than do passenger cars for the exact reason you state (Bosch and others have separate pump solutions for those application than for passenger cars). They also have much lower hp/liter outputs and lower peak rpm's for similar reasons. They are much more robustly designed and that is reflected in the cost of the units and $/liter of engine displacement.

And again, Bosch has made 3 revisions to the VW HPFP to deal with the problem of "poor quality fuel" in the US.



Pierre Louis said:


> Of course future fuel pump designs with higher pressures will need to be more robust. At what cost and what failure rate will the best compromise occur? Certainly the VW/Bosch CP4.0 appears like it didn't cut it with even its low (1% per year?) but still-too-high failure rate, but our 335d CP3's seem to be doing fine, especially with their extra coated parts for North America and BMW's fuel nozzle restrictor in there from the beginning!


The future is here for the VW's. The CP4 is operating at ~29000 psi in the VW. That's ~26% more than our 335d CP3 23000 psi system (I have measured Bavarian Technic data from my car that verifies that peak rail pressure is 1600 bar or 23000 psi if you'd like to see it). Those higher pressures and the CP4 design put much more stress on the pump. Therefore it should be no surprise its more sensitive to marginal fuel and is a big reason why in the field we are seeing higher failure rates with these pumps and why Bosch and VW have been scrambling to contain the problem (with 3 separate pump revisions to deal with "poor quality fuel").



Pierre Louis said:


> Sure, bad lubricity will cause pump failures. That's not the point. When in the field the plurality of pump failures are more likely from misfueling, one needs better statistics to show that lubricity improvement will make enough of a difference.


The data linked in my posts above show this. Lower lubricity shortens lifespan of the pump in a measurably, quantifiably, and reproducible way. Its backed up with controlled studies and in the field (examples linked in previous posts).



Pierre Louis said:


> The better question is what should the consumer look for when buying a new diesel and where should they look for engineering developments to go!?
> 
> PL


Excellent question! I think anyone spending this type of $ on a new car should carefully investigate the pump robustness in real world environments. For me, this meant I held off on buying the VW due to the number of catastrophic fuel system failures I was reading about on TDIclub by the early adopters. Disproportionately higher than the earlier PD and VE TDI's&#8230;. Having a CP3 HPFP in my Cummins and not seeing problems in the field I was keeping an eye on the BMW due to it still using the CP3.

The design of the CP4.1 looks like a cost saving approach to me. But the way its designed it puts much more stress on the surfaces inside the pump. And the way its designed, when it does fail, it sends shrapnel through the entire fuel system! As a design engineer I can't fathom how something like this made it out the door unless the engineers were over ruled by the accountants &#8230; If there was a way to contain the contamination when the HPFP starts shredding itself, this would control the cost associated with the failure. Until something like that is in place I don't plan on buying a vehicle with that kind of pump.

Some excellent differentiation between the CP3 and CP4 here that's easy to follow. Especially posts 2688 and 2690

http://forums.tdiclub.com/showthread.php?t=308323&page=180

The CP3 is much, much less likely to contaminate the entire system (injectors). The CP4 just screws everything up when it goes.

Delphi has a neat approach to help reduce one of the wear/catastrophic failure mechanisms the Bosch pump suffers from.

http://delphi.com/about/news/media/pressReleases/pr_2010_05_11_001/
_
The roller cam shoe mechanism has been optimized for reduced torque, dynamic mass, and noise via the Delphi patented static shoe guide. The component is pressed straight into the housing so that the shoe guide, different from previous solutions, does not oscillate during pump operation keeping the dynamic mass low, permitting a small plunger return spring size and optimum packaging geometry. The design safely prevents the shoe on the DFP6 pump from lateral rotation which eliminates the risk of fatal pump damage and allows for a mass of just 2.4kg. _

The NHTSA investigation challenged Bosch on this issue by the way.


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## FredoinSF (Nov 29, 2009)

Interesting thread although some of the info goes way over my head. I've had BMW's for a long time and have lots of opinions on many BMW related topics, but I'm a newbie when it comes to the diesel thing.
Based on reading the info here, it seems like the ideal (if there is such a thing) diesel fuel to feed a BMW is a B1 to B5 blend. Is the bio content info supposed to be present on the pump like it is for gasoline and ethanol? I drove around to a couple of station around Reno yesterday to look for bio content info and saw nothing. Does that mean they have 100% petro? 
Sorry for the noob questions, don't want to pump anything greater than B5 without realizing it.


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## Pierre Louis (Oct 23, 2011)

The problem with HPFP failures is turning out to be poor fuel pump design of one pump, the VW/Bosch CP4, from misfueling or storage tank contamination with gasoline. It is unlikely that biodiesel blending or any other lubricity improvement will solve this. VW is now using the fuel nozzle device to prevent misfueling and is retrofitting older HPFP cars with it.

BMW has already been using this device in US diesels:

From:
View attachment Operating Fluids - Fuel System.pdf




> 5.0 Fuels for Diesel M57 D30 T2 US Engine
> Diesel fuel is obtained from distilled crude oil. The distilling process is highly complicated, involving precise control of temperatures and pressures. The diesel fuel quality will vary depending on the refining process and the crude oil source.
> BMW of North America LLC recommends using automotive diesel with a minimum cetane rating of 51 in the E90 335D and E70 X5 3.0D. Never use other fuels such as marine fuel or heating oil, since these fuels do not have the appropriate additives or cetane values. The cetane number is a measure of the fuel's ignition quality, which influences both the ease of starting and combustion stability. A high cetane number diesel fuel promotes spontaneous burning of the fuel, which is beneficial in a diesel engine.
> The only fuel approved is Ultra-Low Sulfur highway Diesel. ULSD contains a maximum of 15 parts per million (ppm) of sulfur. Low-sulfur diesel (LSD) should never be used, because it contains a much higher concentration of sulfur (up to 500 ppm), which can damage the diesel particulate filter (DPF) as well as increase exhaust emissions.
> ...


PL


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## Pierre Louis (Oct 23, 2011)

From a letter from VW to the NHTSA regarding the CR HPFP failure investigation: page 32:


> In summary, nearly 90% of the vehicles evidenced gasoline contaminated diesel fuel to be the cause of the failure.


PL


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