--- In "What Viscosity Should I Choose?", the author of The Motor Oil Bible discusses the primary issues that should be considered when choosing a motor oil viscosity. 1,000 Free copies of "The Motor Oil Bible" being given away. Find out how to get a copy. Motor Oil Questions: Answered. Synthetic oil, motorcycle oil, diesel oil, oil & air filters, viscosity, drain intervals, etc. If it's a question about oil or filters, The Motor Oil Bible answers it. Distributed by Tubemogul.