Power consumption with PÖL higher / how does the power consumption display work?

Touran 2.0 TDI 140 hp.

Today, I added 15 liters of rapeseed oil to the almost empty tank. As a result, the fuel consumption, which was previously around 6.0-6.5 (liters per 100 km) according to the display at 120 km/h, increased to 7.5-8.0 (liters per 100 km).


Since I don't actually believe that the consumption is much higher when using 'Pöl,' I think it's due to the measurement parameters being used to determine the consumption.

In this context, I am interested in understanding exactly how the consumption works.


After driving the tank almost empty again today, I refueled with Dino gasoline, and the fuel gauge was showing 6-6.5 out of 120.

Sure, here's the translation:

'Hi engl.'

Since PÖL is more viscous than Dino-Diesel, it needs to be injected over a longer period to effectively deliver the same amount. In your case, the longer opening time of the injectors is calculated by the engine control unit (ECU) as increased fuel consumption. If the PÖL becomes similarly fluid due to a higher temperature, the difference should decrease again.

Hmm, I suppose that wouldn't happen when running at full throttle, right? After all, the fuel injection system should inject as much fuel as the engine control unit allows. "This would mean that a higher viscosity requires less injection, leading to a loss of power at full load."

Marzocchi wrote:

Hmm, that probably wouldn't happen at full throttle, right? After all, it should inject fuel for as long as the engine control unit allows it. It would mean that the higher viscosity results in less being injected => power loss at full load....

Okay.

In the partial load range, you can increase the throttle to compensate for the power loss, resulting in a higher fuel consumption reading, even though not proportionally more fuel is being injected (as Hati already mentioned).

The entire process can be verified by comparing the displayed average consumption with the calculated consumption based on the amount of fuel added during the night.

Theoretically, even in non-electronically controlled, indirect injection engines like the older G2, G3, and T3 models, a power loss should be noticeable under full load, even with a warm engine. Even with efficient heat exchangers, "Verheizungen" (a term referring to excessive fuel vaporization), and temperatures reaching 70-90 degrees Celsius, the PÖL (presumably a specific engine component or measurement) reaches a temperature where the diesel's viscosity changes. However, experienced PÖL users often report no noticeable power loss. This is strange. Perhaps larger injectors would be beneficial. Similar to what's done with VP TDIs, but not as a tuning modification, but rather as a completely harmless compensation. Possibly, the ESP (Electrostatic Precipitator) might even be slightly relieved because the viscous sludge is a bit easier to handle.

Hello,

It's also important to consider which type of rapeseed oil you're using. Cold-pressed oil has a higher energy content than diesel, which reduces fuel consumption. It increases slightly with refinement.

Best regards, Rodion.