After reading posts on BITOG for the past few weeks, I've observed that most of the discussion is very technical and beyond the scope of the average enthusiast. Despite this, there doesn't seem to be too much on the BITOG home page to get the new reader up to speed. I think a FAQ (or a link to an article or articles that serve the same purpose) would be useful. For instance, a lot of posters talk about low SAP content, changes in HTHS ratings, etc. What do all these acronyms mean, and what is the significance of them? Also, a brief summary of the ACEA and API ratings, and why they appear to be diverging would be helpful. The main reason I ask is that I would like to understand the threads that go into detail as to why GC is a good oil and why my German-designed car seems to be a lot fussier about oil than the average American or Japanese-designed oil.