# Liqui Moly 2002 Super Diesel Additive



## lubeto (Dec 9, 2010)

I know that BMW states absolutely no additives in the diesel fuel. However looking at the 
Liqui Moly 2002 Super Diesel Additive it contains only:
75% Petroleum naphta
20% 2-ethylhexyl nitrate (for cetane increasing)
5% tall-oil (natural tree oil for lubricity)
Would that hurt our diesel engines or emission components? Does anybody use it?


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## Pierre Louis (Oct 23, 2011)

lubeto said:


> I know that BMW states absolutely no additives in the diesel fuel. However looking at the
> Liqui Moly 2002 Super Diesel Additive it contains only:
> 75% Petroleum naphta
> 20% 2-ethylhexyl nitrate (for cetane increasing)
> ...


Diesel is a unique brew of ingredients customized from crude oil of various quality/composition. Each refining process and additive package are made to work with each other and are unique to the particular batch/brand etc. ANY additive must show, to be favorable, how it preserves diesel quality AND improves on it.

No such data exist putting both favorable qualities together for currently available diesel recipes found at the pump. The additive manufacturers would be "all over it" if they had such data by publishing it for marketing purposes. But they don't, probably because it doesn't really do anything.

Otherwise, you might be able to use additives for their original purpose, which is to fix a known problem, NOT to use as preventive maintenance, which many people seem to believe in.

PL


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## Michael47 (May 9, 2014)

Seems to me that the only two "known problems" would be lubricity and anti-gel properties. Cetane value is not a problem, although some folks swear by a need for it.

I have 3 diesel vehicles, and a couple weeks ago, when the overnight temperature here set a record at -8° F, one of them had gelled fuel. All three had been filled at different pumps at different filling stations, but it inspired me to throw a shot of anti-gel into the tanks of all of them. It is a major pain in the kiester to have to come-along a vehicle out of the middle of my 1/4 mile long driveway, thank you very much. So even though the other two did not have a gelling issue, it did suggest to me that at least some distributors of diesel fuel did not anticipate such cold temperatures. I am not, however, planning to do that routinely.

As for lubricity, probably the best lubricity additive is biodiesel, and while it only requires around 1% biodiesel for lubricity, my 2012 X5 35d fuel tank cap and owner's manual say as much as 7% is permissible.


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## Pierre Louis (Oct 23, 2011)

Makes sense that fuel gelling can occur in Virginia with the latest "climate change." Then of course there are "lubricity" deniers among us.


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## totitan (May 11, 2013)

The diesel sold in the US has considerably less lubricity than European diesel. The European Standard Specification for Diesel Fuel (EN 590) is a HFRR of 460. Here the Diesel Fuel Specification (ASTM D 975) is 520. Michael47 is correct that biodiesel is the best for improving our lubricity. The next best is Optilube which will bring lubricity HFRR to 317 by adding 1/2 oz per gallon. The lack of lubricity has not been that much of a problem in our cars but it has been with VW tdi engines. I own one of each and strongly believe that increasing the lubricity is a good thing.....even though PL will undoubtedly disagree ;p


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## Pierre Louis (Oct 23, 2011)

totitan said:


> The diesel sold in the US has considerably less lubricity than European diesel. The European Standard Specification for Diesel Fuel (EN 590) is a HFRR of 460. Here the Diesel Fuel Specification (ASTM D 975) is 520. Michael47 is correct that biodiesel is the best for improving our lubricity. The next best is Optilube which will bring lubricity HFRR to 317 by adding 1/2 oz per gallon. The lack of lubricity has not been that much of a problem in our cars but it has been with VW tdi engines. I own one of each and strongly believe that increasing the lubricity is a good thing.....even though PL will undoubtedly disagree ;p


I'm well aware of the bias that exists on TDIClub in favor of added lubricity. What I know is that there is little evidence pointing to lubricity as the cause of the HPFP "failures" where the data found just as many fuel pumps with no defect as they did fuel contaminated with gasoline. Lubricity was not well represented as a cause of these failures. VW's interpretation of gasoline contamination as the biggest problem was likely the best answer, but the true believers continue on. Who am I to change their mind, especially when there is some evidence that lubricity helps - perhaps for a poorly designed fuel pump!

PL


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## totitan (May 11, 2013)

PL..... the VW pump used from 09-12 definitely falls into the "poorly designed fuel pump" category. It is cheap insurance to supply it with fuel that has better lubricity. I strongly disagree with this statement of yours " Lubricity was not well represented as a cause of these failures. VW's interpretation of gasoline contamination as the biggest problem was likely the best answer". However since Im really not enthusiastic about getting into a pissing contest with you I will leave it as a topic that we can agree to disagree on.


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## Pierre Louis (Oct 23, 2011)

totitan said:


> PL..... the VW pump used from 09-12 definitely falls into the "poorly designed fuel pump" category. It is cheap insurance to supply it with fuel that has better lubricity. I strongly disagree with this statement of yours " Lubricity was not well represented as a cause of these failures. VW's interpretation of gasoline contamination as the biggest problem was likely the best answer". However since Im really not enthusiastic about getting into a pissing contest with you I will leave it as a topic that we can agree to disagree on.


So you agree with me on the pump, which is still just a theory. The rest is not a matter of argument. The evidence is weak (reading ASTM rationale for current specs, with the exception of pump manufacturers who also did not recommend any aftermarket additive by the way), so there is no need to disagree at all. Nothing stops manufacturers from recommending specific additives, but they haven't done that as they have in the past for certain gasoline engines (i.e. Techron for exhaust valve deposits) and synthetic oils (Toyota for engine sludge and Mazda for sticking lifters). There was even a fight between US car brands and Japanese over, as I recall, overhead cam vs overhead valve engine issues (US manufacturers didn't want the higher standards).

Cheers

PL


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## MotoWPK (Oct 5, 2012)

It's also worthwhile to keep in mind that the diesel fuel you purchase at the pump already has additives for lubricity, anti-corrosion, cetane improvers, corrosion inhibitors and pour point reducers (aka anti-gel, seasonally). The degree to which additives are used depends on the base stock and refinery process (some refiners may find it more economical to meet requirements through one or both of the latter instead of additives). 

In all cases the fuel manufacturer is aiming to meet the applicable fuel requirements (e.g. ASTM D975), and as any treatment will have a tolerance in its effect, will usually be aiming for a target that is better than the requirements to account for this tolerance. This results in the delivered fuel properties averaging better than the requirements and varying between just meeting the requirements to bettering the requirements by even more than the average. For example, in a communication with an Innospec representative a few years ago, he advised that here in Colorado Conoco, who uses the Innospec additive package, targets for an HFRR lubricity value of 460 micron, vs the 520 ASTM requirement, and that recent tests at a number Conoco stations showed actual values in the 410-420 range.

Additionally, fuel manufacturers tend to use additive packages rather than single additives. As a package developed by an additive manufacturer there is assurance of compatibility of the individual additives, something you don't have when users supplement these additives with off-the-shelf additives. This is probably why auto manufacturers advise against users adding additives - what's delivered from the pump is a reasonably known quantity (barring contamination), but once you start adding to the fuel it becomes somewhat experimental.

I followed the VW TDI HPFP fuel pump failures quite closely for a few years, when I owned an '09 TDI. While the conclusion was not clear, IMO there was reasonable cause to suspect that lubricity was a significant factor...with those pumps. As other diesel vehicle manufacturers were not suffering significant failures in the US, and using the same fuel as the TDI's, the issue was certainly a matter of or strongly influenced by a poor fuel pump design.


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## n1das (Jul 22, 2013)

Pierre Louis said:


> Makes sense that fuel gelling can occur in Virginia with the latest "climate change." Then of course there are "lubricity" deniers among us.


The fuel down there might not be winterized or winterized as much as it would be in colder regions up north. OTOH, it might have been due to ICING from condensation due to WATER in the fuel and not actually gelling, even if the fuel was properly winterized. People often mistake icing for gelling. They think they have gelling but actually have icing instead.

All diesel fuel has a few PPM of dissolved water in it. It's slugs of free water that are bad and are to be avoided. Slugs of free water will kill a HPFP in a CR diesel in no time at all just like it will kill a rotary injector pump in an older diesel.  Free water in diesel fuel is to be avoided at ALL costs! 

To help prevent getting watery fuel especially during winter months, I only fuel up at busy high volume / high turnover truck stops and busy gas stations along major routes. I go where the big rigs go to get the freshest diesel fuel in the region. Fuel turnover is highest at these stations as the fuel is constantly being replaced, often daily. It is not uncommon for a busy truck stop on a major route to do more than $30k of diesel business in a single day. I specifically AVOID filling up at stations that rarely get any diesel business, no matter how tempting the slightly lower price per gallon may be. Over the years I've developed a list of "trusted" sources for my fuel among the busy stations in my area.

If I'm not going to drive one of my diesel vehicles for a while, I park it with the tank totally FULL to prevent condensation as much as possible. I also regularly use an additive to take care of any water that I can't avoid getting even at the busiest stations.


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## n1das (Jul 22, 2013)

MotoWPK said:


> It's also worthwhile to keep in mind that the diesel fuel you purchase at the pump already has additives for lubricity, anti-corrosion, cetane improvers, corrosion inhibitors and pour point reducers (aka anti-gel, seasonally). The degree to which additives are used depends on the base stock and refinery process (some refiners may find it more economical to meet requirements through one or both of the latter instead of additives).
> 
> In all cases the fuel manufacturer is aiming to meet the applicable fuel requirements (e.g. ASTM D975), and as any treatment will have a tolerance in its effect, will usually be aiming for a target that is better than the requirements to account for this tolerance. This results in the delivered fuel properties averaging better than the requirements and varying between just meeting the requirements to bettering the requirements by even more than the average. For example, in a communication with an Innospec representative a few years ago, he advised that here in Colorado Conoco, who uses the Innospec additive package, targets for an HFRR lubricity value of 460 micron, vs the 520 ASTM requirement, and that recent tests at a number Conoco stations showed actual values in the 410-420 range.
> 
> ...


All good info. I owned a 2010 JSW TDI and put 102k miles on it in a little over 2 years before I sold it to a TDIclub GURU in the Boston area. I ALWAYS used additives to help add lubricity, add anti-gel for winter temps, and to take care of any water in fuel. Providing Cetane boost was of secondary concern. Zero HPFP issues.

One thing I suspect although not proven is a number of TDI HPFP pump failures may have been due to WATER IN FUEL. Those owners should have changed where they fuel up. Some of them had multiple failures. And some have used Bio-D and still there were failures. Aside from providing additional lubricity, taking care of any water in fuel is one reason why I choose to use additives in my BMW diesels, regardless of BMW's no-additives stance.

I'm not surprised BMW says no additives because they can't get involved in endorsing one particular additive over another when the long term effects are unknown. Their no additives stance is also to guard against using old school home made witches brew additives like used engine oil or others like Marvel Mystery Oil.

Additives I choose to use are on the EPA's list of approved ULSD-compliant additives. My favorite is Howes Lubricator Diesel Treat. I have over 700k miles of experience with using Howes in my diesels. I figure I must be doing something right given that I've never had a fuel related issue in any of my diesels in 13 years of diesel ownership. I also live up in the northeast where it gets cold enough to have gelling problems if fuel isn't winterized and icing problems if there's moisture in the fuel.

Good luck.


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