Greetings all, new to this forum and advice on an old favourite topic please. Not new to Mercs but am new to a 2004 Vito CDI 111 and was wondering if I could be ok to run it on a mix of diesel and new cooking oil. Did this on an old 300 6 pot no problem with about a two thirds diesel to one third oil but I gather more modern engines this can be a problem. Have done a bit of searching and some seem to rule against it while others suggest it should be fine. Quite keen to bring running costs down as we have a costco close by where I can by 20litres of the stuff very reasonably but if this results in expensive garage bill then will not be popular. If it is just a question of a fuel filter change then no sweat but not sure if this is a common rail or whatever they call it and causing major issues. As you can see no expert and any help appreciated.