Agree, I test used engine oils and I've seen a increase in numbers since the start of Biodiesel. Thing is the OEM's never used Biodiesel as a reference fuel when testing the engines.
Who knows what it does in the long term.....What I see is a massive increase in engine oil fuel dilutions. Typical 6-7% and upwards. The average fuel dilution (if any) before biodiesel was on the UK scene was 1-2% max (unless major engine problem)
I think the goverment put lots of pressure on OEM's to included that biodiesel is ok to use now in car handbooks.
I've also read this, due to an increase in unburnt fuel slipping passed the pistons. Biodiesel also has great lubricating properties and I can't see it being a problem with regular oil changes every 10k miles. I'm keeping an eye on the oil also. Still if it goes all tits up in the coming months I'll let you all know!