Endless discussions about this over the years. Adding two-stroke oil is generally agreed to be a good thing with traditional diesels. However I have read that there could be problems with excessive ash going into the dpf. As I recall the advice was to use only semi-synthetic (not oil-based and not fully synthetic). There was a very long thread on this on the FL2 forum. Again going back in time, when dpfs were first fitted I was told by a LR Experience instructor that using premium diesel avoided dpf problems. There seem to be lots of opinions here - I won't use two-stroke oil in my MY19 Evoque for the same reason I won't use bio diesel - these were great in the old diesels but I think the latest ones are so sensitive it's not worth the risk. I would prefer to use premium fuel nowadays, but as someone stated above, the price difference between my local BP garages and Tesco/Sainsburys is ridiculous, even though the premium fuels do give better mpg. I'm inclining to the idea that under current circumstances, doing less than a third of my normal mileage, it might be best to switch to the premium - it can't hurt and may well protect the motor and the dpf. That said, I normally use Tesco and I've only ever had one dpf problem, and that was down to a faulty dpf.