It has baffled many, and still does!
One explanation is that the mid/low saps gets burnt more easily amd actually loads the dpf with ash much more prominently than the full saps under certain conditions, so although the full saps is more poisonous, it can cause less trouble.
I dont recall all the detail, this is very recent news and isnt well established yet afaik, I need to do more study in this area to fully grasp the subject. This is a very vague summary of what has recently been found but gets the main point across.
|