DNA wroteThe guys are not joking as what they said is true, not everything oil companies mention is true most are just for marketing purposes.
@vegetaleb what the mechanic told you is alright, it doesn't really matter just change the oil before the 5000km.
You need to research a bit more ...beside the low burning point of vegetable oils and their very low viscosity....their content in carbon will oxidize and carmalize creating a phenomenon called the black sludge .
Tons of additives need to be added in order to use vegetable oil as motor oil .
There is no need for tin foil hats .. this is not only marketing