The primary purpose of writing this book is to make available to the students, researchers and is prepared for case study projects. The current research deals with the reduction of wear and friction of automotive engine and gear components, and improving the performance of the IC engine by dispersing with multi-wall carbon nanotubes addition as additives in lubricating oil and gear oil. The wear scar diameter of the balls of the lubricating oil and gear oil with MWCNTs is found to be reduced compared to the base oil. The 0.5 wt% and 10 hr ball-milled shows reduced average wear scar diameter and the friction coefficient is also found similar to that wear results, the better friction coefficient is found at 0.5 wt% when ball milled for 10hrs. The extreme pressure properties of gear oil with nanotubes improved the load wear index and weld load of the gear oil.We wish to acknowledge the many helpful suggestions of reviewers and various industry experts which have certainly improved both the contents and quality of the material. We extend our gratitude to the authors from whose work some excerpts were used in this book.