We're trading in our Q5 hybrid for a Q5 TDI and there are some places near us that sell biodiesel. There seems to be some bias against biodiesel and I can't quite figure out why.
Posts in this forum mention that if you use above a 10% biodiesel mixture, you should get the oil changed more often. Why? I ask because some places near me sell 99% biodiesel! I've read recommendations that say during cold months you should do a 25/75 split. There appears to be a wide gap between what's available and what's recommended, allowed or considered harmful for your car.
Can anyone help me cut through all the messaging?