BIODIESEL im Test | Posts 16+

Hi,
What are just two years? Ten or sixteen years is more likely what a pump should last, even though not all of them can achieve that, even with mineral diesel.

However, with 160,000 km driven in two years, there is certainly no risk of condensation, resin and acid formation, or biofilm development. After all, the system always contains fresh biodiesel.
However, this is usually not the case with other people.

Okay, I don't understand what you guys always want with Polo.

I'm just saying, this is about the G4 engine with ALH and the Lupo SDI.

So far, only good experiences - who else?

Well then, it doesn't matter.

Hello,

I also occasionally fill up my Golf IV, manufactured in 1999, with engine code AHF and 110 horsepower, with biodiesel.
When the car was 4 years old, I noticed that the oil cooler lines had started to leak. The foam padding on the engine cover was soaked with diesel.
I believe the oil return line may have become leaky due to the biodiesel, even though I only used it occasionally. This also poses a risk to the seals in the ESP (Electronic Stability Program).

My opinion is that, even for someone who drives a lot, the risk of damage to the ESP (Electronic Stability Program) is not worth the approximately 5 cents per liter of biodiesel that one saves compared to regular diesel.

Best regards,

Frank.

true words...

LESS,

As I mentioned, I've been using it for 2 years and 160,000 km, and it's been running on biodiesel only, with no problems.

Should this be the exception? Who knows.

best regards


THAT IS the exception!

Here are the main problems associated with biodiesel:

things like water solubility, oxidation stability, and also biological properties. Biodiesel is not stable for long-term storage; it cannot be stored for extended periods. Furthermore, it can provide a breeding ground for bacteria, which can clog filters and, through their metabolism, introduce undesirable substances into the fuel cycle.
'Quite a few farmers looked confused when we tried to restart the combine harvester. It was running so well on biodiesel... now it's broken... because no one told them that they need to flush the system with diesel before storing it for the winter.'

Things like viscosity. Biodiesel is 'thicker' than regular diesel. This puts much higher forces on the injection system and its drive mechanism, especially with cold fuel.

The lubricity. Certainly, the HFRR value is significantly better... but that's not the only factor in a common rail injection pump. As Bertil already hinted, other factors come into play (e.g., kinematic viscosity, compressibility...). High-pressure pumps are already operating at the tribological limit. Therefore, the often-made comparison with the old chamber diesel engines with inline pumps is complete nonsense. Those engines operate at 400 bar at the injector. Our VE pumps, however, already have 950-1200 bar in the high-pressure chamber (1200-1600 bar at the injector). PD pumps have even higher pressures.

And then, of course, there's the long-missing standard! UFOP isn't available everywhere, and even if it is, it can only guarantee so much. You're completely reliant on the honesty of your gas station attendant. Where they source their fuel and what's actually in it doesn't really matter to them; without a standard, no one can hold them accountable. The craziest things have been sold as biodiesel. There aren't quite as many possibilities with mineral diesel.

In summary, you, as a high-mileage driver, likely have a good driving profile if those 80,000 km per year are accurate. You probably have fewer cold starts and the biodiesel isn't sitting in the tank for long periods. My dealer also has a car like that. He definitely uses biodiesel that meets the standards, and he uses it on long distances. It's the only vehicle that the biodiesel hasn't damaged. Otherwise, there's a pile of defective pumps.
'The typical traffic is harmful, even without biodiesel. I know people who can drive for 5-6 weeks on a single tank of fuel. That's absolutely disastrous when using biodiesel.'

CU Gremlin.

So, I don't know what you guys always want with Polo.

I'm just saying, this is about the G4 engine with ALH and the Lupo SDI.

So far, only good experiences - who else?

Well then, it doesn't matter.


Your arguments to my questions don't really excite me.
If you do that, then that's your beer. However, there are countless more arguments against it than for it. At the very latest, when you need a new seal (because it's no longer tight, and few workshops want to risk just a seal replacement), you'll realize what the biodiesel has saved you.

I find the discussion quite one-sided.

el-diesel thinks it's absolutely great.
Although there are many arguments against it.
He doesn't want to be convinced, so let him get his ESP destroyed.


By the way, I also used BD (presumably referring to a specific method or product) with my former ATD (presumably referring to a specific device or system) for about six months.
but: a ~10% increase in consumption reduces the savings.
and after I probably had some old soup reheated for me somewhere during the winter.
(rough cold start, smoke, sputtering)
The €60 service fee for VAG vehicles completely convinced me.

Okay, I continue to use RME because of the 'pore-softening' theory. This theory suggests that seals that have been pre-damaged by RME are more likely to fail when subsequently exposed to Dino again. Or, in other words, a cycle of Dino-RME-Dino-RME...

I cannot confirm the often-cited increased fuel consumption. My last fuel consumption measurement showed 4.8L/100km again. I have to say that my fuel pump has been running in a limp mode for about 2000km due to a stuck fuel injector. It's stuck in a very early position. I won't do anything until I find an inexpensive replacement pump. Partly because I don't want to disable my car for weeks due to a repair attempt on the only existing ESP (Electronic Stability Program). For highway driving, I have an adjustable 0ct tuning that compensates for the limp mode. But I don't need it for everyday use (city and rural driving, max. 80km/h). It's amazing how little power you actually need in city traffic. You only accelerate very slowly, but you're not slower. The only effect is that you brake less abruptly. That's quite something, isn't it?

Regarding the argument about high viscosity: Cars in Norway have to cope with even higher viscosity during cold starts, and this is with regular diesel fuel. (see temperature-viscosity diagram). Do fuel pumps fail more often there due to high viscosity? Or does Bosch offer special 'Arctic Circle' fuel pumps for cars in those regions?

The non-higher consumption of RME compared to conventional diesel (despite its lower energy density) is sometimes attributed to a cleaner combustion process (higher combustion efficiency). With heating oil (and likely also with RME), an increase in the soot limit has been observed, meaning that a stoichiometrically larger amount of fuel can be combusted cleanly per cylinder. RME manufacturers themselves acknowledge slightly higher nitrogen oxide emissions, which suggests higher peak combustion temperatures, which is thermodynamically advantageous. This, in turn, confirms a higher combustion efficiency.

There are many drawbacks, but also many advantages.

As often happens, it's not so easy to divide everything into simple categories of good and bad.

Best regards,

SeatArosa1.7SDI wrote:

..... Regarding the argument of high viscosity: Cars in Norway have to cope with an even higher viscosity during cold starts, and this is with normal diesel fuel. (see temperature-viscosity diagram). Do the pumps fail more often there due to high viscosity?

That is indeed the case. More ESP (Electronic Stability Program) units fail in colder regions than in warmer areas. Unfortunately, I can only provide information for Delphi systems. I cannot say what the situation is like with Bosch.
People who live in areas with such extreme weather conditions are aware of the problem of the increased stress placed on materials.
However, the defects that occur are more likely to be long-term consequences. In other words, the pumps don't break down immediately.

There might be something to the theory of exclusively using one brand of gasoline. The only people I know who claim to have "no problems" with using a specific brand of gasoline drive extremely high annual mileage and exclusively use that brand (and even always get it from the same gas station).

That is actually true. More ESPs (Electronic Stability Programs) fail in colder regions than in warmer areas. Unfortunately, I can only say that for Delphi systems. I cannot say what the situation is like with Bosch.

behaves the same way...

CU Gremlin.

Conclusion: The ideal RME-ESP would consist of stainless steel and/or ceramic components and would, of course, use only Viton seals.

And it would have a cleaning mode using pure acetone to dissolve any bacteria and grease buildup every 2 years.

Best regards,

Conclusion: The ideal RME-ESP would consist of stainless steel and/or ceramic components and would, of course, have exclusively Viton seals.

And it would have a cleaning cycle using pure acetone to dissolve bacteria and grease buildup every 2 years.

Regards
Hi,
That would probably be an exaggeration. But it's likely that the pumps are designed for Dino-Diesel. And they are designed to be economical, which means they are built as well as necessary and as poorly as possible, in order to keep the price within a certain range.
If the specifications for the pump manufacturer were to be changed to include biodiesel compatibility, the pump would likely become significantly more expensive because certain components would need to be modified. However, no one is willing to take on that task.
As long as there's still plenty of Minol available, things probably won't change. Let's see what happens when the price of Minol reaches 3-4 EUR per liter, because the oil reserves are almost depleted...

Greetings.

Eike.

As long as there is still enough Minol available, things probably won't change. Let's wait and see what happens when Minol costs 3-4 EUR per liter, because the oil reserves are almost depleted...


A production-ready ESP (Electronic Stability Program) specifically designed for RME (Rail Maintenance Vehicles) or even PÖL (Passenger Onboard Lifting) is unlikely to exist.

The automotive industry and oil companies want to pursue a different approach. Instead of adapting engines to run on naturally derived fuels, they want to adapt the fuels to increasingly sophisticated engines.

Keyword 'Designer-Diesel' or 'Sunfuel': Here, using a complex process, any high-purity hydrocarbons can be produced from biomass and energy-rich waste. Here is a link: http://moderntimes.orf.at/web/Beitragneu/s2004_03_05/beitrag2.html

A disadvantage of using raw biofuels (PÖL) directly is the enormous energy expenditure, or the poor energy yield, from the biomass, as so much energy is lost as process energy. This is even more pronounced than in the production of biodiesel (RME), which is still relatively simple.

It is advantageous that designer modifications can optimize engines in terms of both power-to-weight ratio and particulate emissions.

However, engines that are optimized for unprocessed biofuels would be more energy-efficient overall, allowing for a system where crops can be harvested directly from the field, processed, and then used as fuel.
However, the political will is lacking. And perhaps also the acceptance among car drivers, because these 'puddle-oil' engines would have the mass-to-power ratio and temperament of old W123 diesel engines. And they would also emit visible particles.

Regards,
Holger.

Hello everyone,

Here's a brief overview of my experiences with biodiesel:

'I drove a Golf 4 with a 90 HP ALH engine and a rotary injection pump for about 3 years, covering approximately 150,000 km, almost exclusively using biodiesel, and I never had any problems.'

After I got a new Golf 100PS AXR PD in December 2002, I initially thought about continuing these fueling habits.
After the third tankful at 10°C, I voluntarily stopped using it, as the exhaust smoke during startup was concerning. My subsequent online research also revealed that driving instructors and other experienced drivers had only negative experiences using biodiesel in conjunction with newer high-pressure systems (CR, PD), encountering issues like new PD injectors, and subsequently switched back to conventional diesel.

Regards,
VG

However, the political will is lacking. And perhaps also the acceptance among car drivers, because these 'puddle-oil' engines would have the mass-to-power ratio and temperament of old W123 diesel engines. And they would also emit visible particles.


I still don't believe it. You can adjust a TDI engine to suit the viscosity of the oil, so why not also adjust it to allow for cold starts with that oil?

Best regards, WarLord.

because the fuel injection system can only be optimized for one type of fuel.

... unless someone manages to outsmart physics.

Sure, here is the translation of the text from German to English:

'Cu Gremlin'