Sulfur Content & New PD TDIs

Hi,

A friend of mine wants to take a TDI car to the USA/Mexico.

He is now wondering whether the usual 50 ppm sulfur content used in Germany is also "necessary" for these engines.

Because in Mexico, the law allows for 300 ppm, and in some states in the USA, the limit is 500 ppm.

Does sulfur damage a TDI engine produced in Germany?
He said he wanted to get a Polo with either 100 or 130 horsepower.

m;

Hi,

The varying sulfur content in the fuel (currently, in my opinion, less than 10 ppm is common in Germany) has no significant impact on engine durability or driving performance. It might slightly accelerate the aging of the catalytic converter and exhaust system. Furthermore, it will slightly increase particulate matter emissions (by about 5%).

Best regards,

According to www.aral.de, the value is 50 ppm.

Hi,

Great website - definitely worth reading.
However, as you can find out there: Legally required for EU4 is 50 ppm (low sulfur), while below 10 ppm (sulfur-free) is voluntary due to tax benefits.
The same thing happened with the EU3 standard before 2005, where 350 ppm was required, but 50 ppm was tax-advantaged - therefore, most manufacturers naturally only offered 50 ppm.

I've done some more research. In Germany, <10ppm is common. Money makes the world go round.

Best regards,

[Translating...]

http://www.aral-forschung.de/forschung/homepage/kraftstoffe/dieselkraftstoffe/physik0/schwefel.html

...
The different sulfur content (10/50/500 ppm) in the fuel has no significant impact on engine durability or driving performance.
...

Unfortunately, that's incorrect!

PDEs tend to form more scale/crust more quickly at higher sulfur content.
Unfortunately, the self-cleaning function that removes soot buildup from the nozzles is not as well-developed in PD engines. Therefore, PD engines require a low sulfur content in the fuel.
Therefore, the driving characteristics will only change over time.

Small consolation: even in the USA, they are currently switching to fuels with lower sulfur content. Unfortunately, these are not yet widely available due to the government's blocking policies.

Hi Goettmann,

I'm not very familiar with 2nd generation PDEs, so I need to ask again why the installed nozzles are supposed to coke up faster with a higher sulfur content.
In my opinion, this is a general problem related to the ever-decreasing hole diameters. If nozzles become clogged due to sulfur deposits, leading to blockages and, consequently, injection problems over time, shouldn't all modern direct injectors experience "clogging problems" with higher sulfur content? This is because the hole diameters and nozzle geometries of these direct injectors are comparable to other designs.
The engines or particulate filters (PDs) in question were all developed at a time when 350 ppm fuel was the standard in Europe. Therefore, one might expect that the wear characteristics or performance of these PDs would be noticeably affected and dependent on the regional sulfur content.
I learned that the coking process is highly dependent on factors such as nozzle position and combustion method, and also on the ash content of the fuel. Bosch doesn't provide any information about the maximum sulfur content in its data sheets either - do you know more about that?

Best regards,

...
I'm not very familiar with second-generation PDEs.
...

That has nothing to do with PDE generation.

In my opinion, this is a general problem related to the increasingly smaller hole diameters.

No (at least not primarily)!
The problem affects all HD Di Diesel systems.
Yes, even HD Di Benzin systems absolutely require low-sulfur fuel.

If injectors become clogged due to sulfur content, this can lead to injection problems over time. Shouldn't all modern direct injectors, with their comparable hole diameters and injector geometries, experience 'clogging problems' with higher sulfur content?

Yes, that's exactly the problem.
Unfortunately, I can't precisely describe what exactly happens, but in combination with the sulfur, various substances react to form a soot-like mass, which leads to the 'fouling' of the nozzles with combustion residues.

The engines or particulate filters (PDs) in question were all developed at a time when fuel with 350 ppm sulfur content was the standard in Europe. Therefore, one might expect that the wear characteristics or performance of the PDs would be noticeably affected and dependent on the regional sulfur content.

'Well, maybe... one of the requirements of the HD system developers was low-sulfur fuel. This also fit perfectly into the 'eco-friendly' concept (what a coincidence ).'
While the systems were designed to operate safely at 300-350 ppm, in the US, for example, there is currently a standard that allows up to 1250 ppm. Only in a few states (including California) has the permissible sulfur content been reduced to 350 ppm. Nevertheless, even in these states, fuel with 1250 ppm is still occasionally found.
Unfortunately, I don't have any data available for Mexico.

I once learned that coking is strongly dependent on, on the one hand, the nozzle position and combustion process, and on the other hand, on the fuel's ash content. Bosch also doesn't provide any information about the maximum sulfur content in its data sheets - do you know more about that?
Okay, that's correct. The combustion process changes significantly along with the higher (possible) injection pressures. That's essentially what all the development is focused on. There's been a lot of discussion about this in this forum already.
I would also be interested in knowing exactly what happens in connection with the sulfur compounds. Unfortunately, there is very little information available about this. In any case, the mechanical wear resistance is primarily not related to the sulfur content. It is a problem that arises from the combustion process and its residues.

Hi goettman,

Thank you for the answers.

I understood Dieselmartin's request to be whether the current EU4 PD engines from VW specifically have a problem due to their unique injection system and the higher sulfur content. So, we can deny that, although I know you believe that all modern diesel engines from any manufacturer will have problems with this.

goettmann wrote:

The problem affects all

HD Di Diesel systems.
Yes, even HD Di Benzin systems absolutely require low-sulfur fuel.
http://europa.eu.int/comm/environment/air/pdf/2005_0069_de.pdf

goettmann wrote:

shows the fuel qualities in Europe, and even now, it has not been possible to offer low-sulfur fuel throughout Europe. Sulfur levels of over 300ppm are the norm in Italy, Portugal, etc. I don't even dare to post about what it's like in Eastern Europe, China, Brazil, etc. 5000ppm is not uncommon there. Despite this, the same engines with the same fuel injection systems are sold throughout Europe/the world (with exceptions), and while the proportion of diesel vehicles is significantly higher in countries like Italy compared to Germany, how does this reconcile with the logic that diesel vehicles in Italy should, and must, have a shorter lifespan than in Germany?

Unfortunately, I cannot precisely describe what exactly happens, but in combination with the sulfur, various substances react to form a soot mass, which results in "coking" of the nozzles with combustion residues.

goettmann wrote:

;)Yes and no... one of the requirements of the HD system developers was low-sulfur fuel. This also fit perfectly into the "ecological concept" (what a coincidence

).


Das ist auch mein Wissenstand, keiner weiss genau wie das funktionieren soll noch gibt es fundierte Studien, aber die Hersteller der Einspritzausrüstungen weisen gerne bei Verkokungen auf die Kraftstoffqualität und die Motorenentwickler weisen bei Verkokungen gerne auf die Hersteller der Einspritzausrüster und ihre mangelnde Konstruktion hin. ScHönes game.
It is also a fact that any components in the fuel that do not participate in complete combustion can also lead to deposits, and if you reduce that proportion, you will certainly reduce the amount of deposits.
It is also a fact that, even with completely sulfur-free fuel, the phenomenon of increasing injector nozzle openings with decreasing injection rate over time still occurs due to deposits.
The truth, as always, lies somewhere in between, but as long as the new car buyer doesn't notice anything within the first 150,000 km, everything is fine. }

....
Despite this, the same engines with the same fuel injection equipment are sold throughout Europe/the world (with exceptions) ...

Small note...
Up until model year MJ04, the USA was an exception. PD engines were not sold there due to the poor fuel quality. It was only with the MJ05 that PD engines were introduced. Before that, there was a good reason why only VP engines were available.
The PD engines offered in the US are 'detuned' compared to the EU models. It's important to be aware of this, and I have no idea what modifications were made. Personally, I wouldn't drive a diesel vehicle from the EU given the poor diesel quality.

As far as I can recall from the question, it also involved the USA... Or did it?

Hi goettmann,

The topic is really interesting, and we're learning a lot from our discussion. Hopefully, it will also be interesting for others.

You are absolutely right that VW PD-TDI engines were not sold in the US until recently, and one reason for this was the fuel, but in my opinion, there was another reason as well.

Background:
In the US, diesel cars have almost no market share, accounting for only 0.5%. Volkswagen might sell around 500-1000 TDI vehicles per year, so the number being scrapped is relatively small.

The reason for the delayed introduction of PD-TDIs is the current emissions regulations for new vehicle approvals in the United States. These regulations, based on the FTP 75 cycle and the emission limits, were almost impossible to meet for diesel engines due to the poor fuel quality (an example: gasoline and diesel engines have the same emission limits!). Therefore, until recently, it was not possible to obtain approval for a new vehicle with the same EU-spec engine hardware. A special hardware variant for the US market would have been technically possible, but due to the expected production volumes (as mentioned above), it would not have been economically viable.
Therefore, it was only recently achieved (with EU4 hardware and many tricks) to apply the PD-TDIs in a way that they could be certified for the US market. This is also the reason why the US-market PD-TDIs are "neutered"; they have a completely different engine tuning for emissions regulations, even at full load, because the FTP cycle also extends to full load.

So, it has nothing to do with nozzle coking due to an increased sulfur content, and that's actually what the original post was about.

To properly assess the situation, we should force some of Dieselmartin's acquaintances to buy a PD-TDI, drive it across the USA, and report back to us how long the engine lasted using that old fuel.

...
So, it has nothing to do with nozzle coking due to an increased sulfur content, and that's actually what the original post was about.
...

Unfortunately, yes...

In the US, the manufacturer must guarantee that various parts (including the engine) of the vehicle will last for 100,000 miles without problems. This was previously not possible with the unreliable diesel engine. Therefore, there was no consideration given to offering a functional warranty for 100,000 miles.
In addition, there are emissions regulations to consider. That's correct. The emissions regulations are also the reason why the TDI isn't available in California. California has such strict emissions standards that the TDI simply doesn't meet them. People who want to drive a TDI in California often buy it in Arizona or Nevada and then register it in California.
According to my information, the PD TDI engine has different part numbers (PDs) in the US. This means there is also a hardware (likely a minor) change.

To what extent this is relevant for the 'average driver' is something each individual has to decide for themselves.

One more thing...
I just checked my documents and saw that the sulfur content in the US was supposed to be reduced to 500 ppm at the beginning of 2005. This should eliminate any problems with the PD (presumably referring to a specific device or system). However, I cannot confirm whether this fuel is available everywhere.

I've heard about that 100% money-back guarantee before - it's true.
Does the manufacturer have to provide the warranty to the customer or to the regulatory authority?

If the warranty applied to the customer, that would be a great thing. Perhaps VW could introduce something like that in Germany. Then I would also buy a new car.

I'll find out on Monday what changes have been made to the US privacy policy elements.

Until then.

I've also heard about the 100tmls guarantee before - it's true.
Does the manufacturer have to provide the warranty to the customer or to the regulatory authority?

The manufacturer must, in the general approval process, demonstrate that their product (on average) can withstand 100 tmls without any issues.
However, this does not (automatically) mean that the customer will receive the 100tmls as a warranty. The purpose of this is to protect consumers from 'low-quality' products.
However, a certain level of failure is still tolerated. It's impossible to have absolutely no defects. The regulatory authorities are also aware of this.

Example window lifter G4:
'This component fails at a rate that is significantly above average in the United States (meaning it doesn't typically last for 100,000 miles). Now, the regulatory authority is intervening and requiring the manufacturer to implement a recall.'
In the case of VW, they were satisfied with a 7-year warranty to avoid a recall.

This process puts immense pressure on the manufacturers. I don't think it's bad. The EU should have something like this too.

Okay, that was definitely off-topic... Sorry.

goettmann wrote:

The PD TDI has (according to my information) different PDEs in the USA as well. Therefore, there is also a hardware (rather minor) change.

As promised, here's a small addition regarding the topic of PDEs in the USA.
The US PD-TDI engines do indeed have different PDEs, but only nozzles with altered spray angles are used, as this was necessary due to the exhaust application (epsilon). This means the same PDE hardware is used for both the EU and US versions.

Furthermore, I have now come to the conclusion that one should not buy a PD-TDI engine if one wants to completely avoid the phenomenon of injector coking, regardless of the fuel used. I was probably too trusting in this regard.

It's funny that goettmann and I, at the end of this thread, are formulating exactly the opposite of what we stated in our initial responses...

At least we've covered the topic of sulfur in some detail.

Best regards,

Here's another piece of information about this.

Here, Peugeot test vehicles are being driven with US gasoline. Additionally, ESP/PD test benches are being used to determine whether the US gasoline can be used in the long term, as its quality seems to be comparable to that of Eastern Bloc fuel from about 10 years ago. In the US, diesel is primarily used as fuel for trucks!

This doesn't just relate to the sulfur content, but to virtually all other quality parameters, such as the cetane number, etc.

Since premium fuel costs more, and the average, older US engines ('dieselized big-block gasoline engines') run on anything that burns, no one offers premium fuel. And if a lawyer proves to a manufacturer that their vehicle is not suitable for US-made fuel, the resulting penalties and consequences can run into the millions.

By the way, sulfur is used as a lubricant in older fuel injection pumps. Older rotary fuel injection pumps tend to fail more quickly with our sulfur-low fuel.

By the way, this also applies to the oil pumps in oil heating systems. According to my heating engineer, the lifespan of the pumps when operating with low-sulfur 'Super' heating oil is 5-7 years. And they only cost around 200€!

'It's supposed to burn cleaner with fewer deposits, which is good. I would even buy it, but not if it ruins my oil pump.'