Belker it would have been cheaper to do more oil changes with the high grade oil and not idle so much , everything is linked once one thing fails like pushing oil changes to the max it effects the turbo then the egr then the DPf, I've never had any dpf problems because I changed the oil every 10k and the DPf gets cleaned out every 250,000km, and I started using circle k miles extra diesel 3c of every litre.