Banasiewicz02 wrote: .... , pour Bio for 20zł,...,there are the same bio-components in this fuel.
Another myth.
The fuel from the Bliska station under the name Bioester is a methyl ester of vegetable oils so it is chemically different from the thermally "crossed" french fry oils. Bio-components are added to other fuels such as ethanol to gasoline. ITD inspectors taking a sample from the tank can determine the composition and origin of the fuel - for example, whether it does not come from Biedronka:0.
Every slow-burning Mercedes diesel burns oil from French fries, oil from Biedronka and Bioester. The difference is that the exhaust gas after Bioester does not smell of fries as it is noticeable with the others. Of course, with the assumption of a well-adjusted pump. Considering theoretically, the basis for sampling may be this characteristic smell. Taking into account the reality I would fill up with normal fuel first of all before visiting the diagnostic station and below +5 C. Despite the heating of the fuel in the Mercedes engine, the problem of starting a cold engine remains - vegetable oils have a higher viscosity (not density) so more suction force is needed to pump it from the tank to the pump at the engine.
BTW I had a 190 2.0D and in winter (even -20C) I flooded it with Bioester from Bliska and it was OK .As for Vegetable Oil I added it to 80% - except in winter, of course.