Again, biodiesel

In this forum, the use of biodiesel has already been extensively discussed. I myself have stopped using biodiesel as a result.

Since I had previously made very good experiences with a 10% addition of biodiesel, I decided to try it again and filled up with a few liters.

The engine now runs noticeably smoother and, subjectively, has significantly more torque. I haven't yet taken any objective measurements, as the weather is also playing a role and distorting the performance figures.

Question: What are the arguments against adding around 10%?

Best regards, Uwe

Question: What are the arguments against adding approximately 10%?



...bosch only releases 5%

CU Gremlin

Hello UWE,

I cannot confirm increased performance, but rather a noticeably higher consumption during mixing. (More than the calculated increase of approximately 1% per 10% concentration)

What I can confirm is the noticeably smoother idle and quieter operation at low loads. I would also be interested in knowing the exact 'why' behind this.

Even if Bosch only allowed 5%, I would not have any concerns at 10%. After all, many people have been driving with 100% for years.

If someone were to pass on the price advantage of adding the concentrate to the customers, I would definitely refuel there. But BP/ 'The Aral oils that are now being added are also among the most expensive, and why should I accept an increased consumption?

The quiet effect also occurs with pure vegetable oil mixed with other oils, but the consumption remains the same due to the higher calorific value of the vegetable oil, without any increased consumption. (Aldi, Lidl, etc. oils)'

garth.brooks wrote:

I cannot confirm increased performance, but rather a significantly higher consumption, especially during mixing. (More than the calculated increase of approximately 1% per 10% proportion)

I will perform the Ulf test and post the results here. However, this will take some time, as I need to empty the tank first.

garth.brooks wrote:

But BP/Aral, which are now also involved, are already among the most expensive, and why should I accept an increased consumption?

Huh? I thought that in France, they mix things together. Do companies like Aral & Co also do that?

garth.brooks wrote:

The "silent effect" also occurs when pure vegetable oil is mixed in, but in this case, the consumption remains the same as with no additional oil, due to the higher calorific value of the vegetable oil. (Aldi, Lidl, etc. oil)

I don't trust that. What if the juice doesn't mix properly and a blob ends up directly in the fuel pump? Can we be sure that proper mixing is taking place?

Best regards, Uwe

Hi Uwe,

it's only really noticeable when refueling. However, because the fuel pump constantly delivers a higher volume of fuel than is actually needed for injection, some of it always flows back into the tank. This recirculation ensures that:

1. The tank remains clean, as all the dirt is forced into the filter,
2. The ESP (Electronic Control Unit) stays cool because it's being cooled,
3. The fuel is thoroughly mixed.

You can also mix petrol and diesel quite well – just give it a try. There are also many forums dedicated to this topic.

I noticed a significant difference in performance, especially at around 30-50%, when the engine is cold. I've been trying for a while now, including heating the ESP and so on, but it's not really worthwhile.

In Germany, adding ethanol is now permitted, and Aral has announced that they will also do so. Whether it's currently possible is unknown to me. (There was a topic about this in the forum a while ago)

[Translating...]

Mir geht es bei der Zumischung von Pöl oder Biodiesel nicht um irgendeine Ersparnis. Vielmehr hat mir das Laufverhalten meines Motors gefallen. Sonst nichts. Nur darauf kommt es mir an.

Ich hab auch schon in die einschlägigen Pöl und Biosaftforen reingeschaut. Die haben aber allesamt völlig andere Ambitionen als ich. Da bin ich mit meiner Fragestellung auch nicht besser aufgehoben als hier.

Ich habe ja schon ca. 80.000 Km mit 10-20% Biodiesel im Tank hinter mir. Davon hatte ich nur ein einziges mal mit Biodiesel voll getankt. Da lief er nicht mehr. Kaumn noch Drehmoment, aber absolut weicher Motorlauf. Auf dsas Zumischen bin ich dann durch den Wechsel auf Dinosaft gekommen. Gleichzeitig hatte ich meinem Auto einen Chip verpasst. da hatte ich noch ca. 10% Biodiesel im Tank. Mein Auto ging wirklich ab wie eine Rakete.

Das gleiche habe ich übrigens bei unseren PD probiert. Eine Leistungssteigerung habe ich icht festgestellt, aber wieder angenehmerer Motorlauf, weniger Vibrationen und leiser.

Meine Fragestellung ist die, ab wieviel Biodiesel im Tank schädliche Auswirkungen möglich sind. Ich habe auch schon gehört, man darf gar nicht mischen...?

Mit der Bosch Freigabe von 5% kann ich schon leben. Vielleicht weiss jemand genaueres?

Gruß Uwe

[Translating...]

Zusatzfrage:

Wie hoch ist die Förderleistung der Dieselpumpe? Also wie lange dauert es, bis ein voller Tank einmal durchgequirlt ist?

Gruß Uwe

[Translating...]also da steht:

'Sie (die Flügelzellenpumpe) förder pro Umdrehung 4,24cm³ Kraftstoff vom Zulauf in den Innenraum der VE-Pumpe'

CU Gremlin

Uwe wrote:

garth.brooks wrote: The "silent effect" also occurs when pure vegetable oil is mixed in, but in this case, the consumption remains the same as with no additional oil, due to the higher calorific value of the vegetable oil. (Aldi, Lidl, etc. oil) I don't trust that. What if the mixture doesn't mix properly and a blob ends up directly in the fuel injection pump? Can we be sure that proper mixing is taking place?

Hello,

the ESP doesn't cause any problems; it's mechanically identical to the VE37, which I use in 4 cars with 100% petrol (or do you have a VP44? I'm not sure what kind of car you have). With a DI (direct injection) system, it's more dangerous that the injectors can freeze, especially in cold weather when the thick fuel doesn't properly atomize and then gets into the engine oil, where it clumps together and clogs the oil passages. However, this shouldn't happen even with up to 30% addition in winter and 50% in summer. If you have a high proportion of short trips or partial loads, it's better to use slightly less (10 or 30%). Our swirl chamber fuel tanks work much better with petrol than with diesel.

Best regards, Uli

The ESP doesn't cause any problems; it's mechanically identical to the VE37, which I use in 4 cars with 100% petrol


NO!

Your common-rail diesel engines operate with injection pressures of around 400 bar.

The element pressure in the VP is therefore low.
Our DI pumps operate with pressures of 850-950 bar (1200 at the nozzle), which makes it very critical if it's not hot enough when operating with pure fuel.

CU Gremlin

Gremlin wrote:

NO! Your common-rail diesel engines operate with injection pressures of around 400 bar. The element pressure in the VP is therefore low. Our DI pumps operate with pressures of 850-950 bar (1200 at the nozzle), which makes it very critical if it's not hot enough when operating with pure fuel.

Hi,

we held a measurement session 2 1/2 years ago, during which we measured the pressure difference between "dirty" diesel (referred to as "Pöl") and test oil in the high-pressure part of the ESP (using a sensor instead of the central screw in the distributor head). The results showed that at 20°C, the pressure of the "Pöl" was approximately 20% higher than that of the test oil. If you consider this to be a critical issue, please let me know. I can't imagine that Bosch would install such a small reserve, which would cause pumps to fail significantly more often. I haven't heard of any TDI engines that have been killed due to "Pöl" (the operating speed of TDIs is simply better suited for "Pöl" than in a VW Bulli, which reaches 3800/min at 90 km/h). I've already done this because of the sludge.
Hot sludge (80°C) is actually about 10% higher in pressure than test oil.

Best regards, Uli

Uli S. wrote:

... But I haven't experienced TDI engine problems due to the fuel filter.

Why? What does the engine dislike about the "Pöl"?

Best regards, Uwe

Uwe wrote:

Uli S. wrote: ... But I haven't experienced TDI engine problems due to the fuel filter. Why? What does the engine dislike about the "Pöl"? Best regards, Uwe

Hello Uwe,

I was away for a few days, so I'm only replying now:

These have perforated nozzles that are easier to clog than traditional nozzles in older engines. Furthermore, they are much closer to the combustion chamber than IDIs. When the engine is cold, the thick oil doesn't properly atomize (and even less so with clogged nozzles), and can reach the cylinder wall, from where it is pushed into the oil pan by the combustion process, passing over the piston rings. There, it polymerizes over time with the engine oil (forming a clump or pudding-like mass), which then no longer performs its function properly -> leading to bearing damage, piston ring wear, etc.
Depending on The engine's performance can also be optimized for diesels (DI) by adjusting the fuel delivery, driving style, and operating conditions. Long distances, infrequent periods with very low load/idle, and few cold starts are particularly beneficial.

With a rotary engine, it's not as important whether the fuel is completely vaporized or not; the main thing is that a small portion ignites. The rest is then injected into the main combustion chamber at high speed and burns there anyway, at least the polymerization problem is not as common as it is with diesels. Good nozzles also improve combustion, make cold starts easier, and reduce smoke/grease odor. 4 boxes, for example, still work perfectly even at -12°C with 100% fuel (it hasn't been colder than this since we started using fuel), and they also run smoothly in neutral after a short distance (1-2km). The only problem is the van (the thermostat is broken (it doesn't heat up properly) and the engine is finished).

Best regards, Uli

[Translating...]

Danke Uli für die umfassende Antwort.

Das mit dem Salatöl werde ich auf jeden Fall lassen.

Ich habe mich aber dennoch getraut, etwas Biodiesel wieder einzufüllen und dann die leistung zu objektivieren. Ich bin davon ausgegangen dass ich damit eine höhere Motorleistung bekomme, wie ich es früher schon beobachtet hatte. Allerdings bin ich jetzt auch nicht schlauer als vorher. Ich hatte in Luxembourg vollgetankt (63 Cent...). Der Motor lief sehr rauh. In D hatte ich 10 Liter Dinodiesel nachgetankt, der Motor lief auf einmal viel weicher. Dann Ulfschen Test -> 5,3 Sekunden. Nach etwa 8% Biodieselbeimischung blieb der erwartete Unterschied im Motorlauf aus, auch der Beschleunigungstest brachte keine anderen Werte. 20 Grad Außentemperatur.

Als es gestern abend kalt wurde, habe ich noch mal gemessen, auch 5,3 Sekunden. Meine besten Werte bei kalter Witterung waren 4,7 Sekunden!

Da scheint sich wieder mal mein LMM zu verabschieden. Ich kann leider keine Werte loggen, da ich nicht über die Soft- und Hardware verfüge. Hat das jemand im Rhein Main Gebiet für mich? Haehnlein?

Wenn ich niemand finde, muss ich wohl auf Verdacht probeweise tauschen oder den Trick mit der Diode ausprobieren. Schaun wir mal...

Gruß Uwe