The booklet with my 2010 Jetta said not to use bio-diesel. But it might be because it’s not uber-green. You might talk to the dealer and ask about it. The injectors are apparently such a delicate high-tech item that the oil requires and additive just for them. 507-00, I think.
This is not a typical diesel engine. It’s much more refined and highly tuned.
That is because of the emmission controls that were added in 2007 if memory servers, that is when the EPA rules changed.
My diesel can,according to the manufacturer,use a maximum of 5% bio diesel.Anything more,they say,and you void the warranty.