AWD COMPONENT ANALYSIS Project Report, May 31, 2016 Contract T8080-150132 Gunter Niederbacher Pilot Systems International Contents 1 Abstract.................................................................................................................................... 6 2 Executive Summary ................................................................................................................. 7 3 Introduction ........................................................................................................................... 10 3.1 Background ..................................................................................................................... 10 3.2 Purpose........................................................................................................................... 11 3.3 Data Sources ................................................................................................................... 11 1 AWD/4WD Systems and Components .................................................................................. 12 1.1 AWD Systems Classification ........................................................................................... 12 1.1.1 Definitions ............................................................................................................... 12 1.1.2 AWD Component Nomenclature ............................................................................ 15 1.1.3 AWD Systems Classification .................................................................................... 15 1.2 Current and Future AWD Systems ................................................................................. 17 1.2.1 System Architecture ................................................................................................ 17 1.2.2 Components / Function .......................................................................................... 22 1.2.3 System Function & Operating Modes ..................................................................... 37 1.3 Comparative Assessment of Positives and Negatives .................................................... 40 1.3.1 Vehicle Architecture ............................................................................................... 40 1.3.2 Disconnect Systems ................................................................................................ 40 1.3.3 Secondary Driveline Torque Limitation & Duty Cycle Management ...................... 41 1.3.4 Full Time vs. On-Demand Systems .......................................................................... 41 1.3.5 Rear Axle Architecture ............................................................................................ 42 2 AWD Vehicles by Make & Model ........................................................................................... 43 2.1 The North American AWD Vehicle Market - Overview .................................................. 43 2.1.1 Fuel Consumption and Vehicle Mass Data ............................................................. 43 2.2 AWD Vehicles by Make & Model ................................................................................... 47 2.2.1 Audi ......................................................................................................................... 48 1 2.2.2 BMW ....................................................................................................................... 52 2.2.3 Daimler Benz ........................................................................................................... 58 2.2.4 Fiat Chrysler (FCA) ................................................................................................... 64 2.2.5 Ford ......................................................................................................................... 74 2.2.6 General Motors (GM) .............................................................................................. 76 2.2.7 Honda ...................................................................................................................... 80 2.2.8 Hyundai (Kia) ........................................................................................................... 82 2.2.9 Jaguar Land Rover (JLR - Tata) ................................................................................ 85 2.2.10 Mazda ...................................................................................................................... 88 2.2.11 Mitsubishi ................................................................................................................ 89 2.2.12 Nissan (Infiniti) ........................................................................................................ 92 2.2.13 Subaru ..................................................................................................................... 94 2.2.14 Tesla ........................................................................................................................ 97 2.2.15 Toyota .................................................................................................................... 98 2.2.16 Volkswagen ........................................................................................................ 101 2.2.17 Volvo ................................................................................................................... 103 3 AWD Efficiency Improvement Potentials ............................................................................ 106 3.1 Definitions .................................................................................................................... 106 3.2 System Level ................................................................................................................. 106 3.2.1 Architecture .......................................................................................................... 106 3.2.2 Disconnect System ................................................................................................ 107 3.2.3 Downsizing ............................................................................................................ 107 3.2.4 Electric Rear Axle Drive (eRAD) ............................................................................. 108 3.3 Component Level ......................................................................................................... 109 3.3.1 Fuel Efficient (FE) Bearings ................................................................................... 109 3.3.2 Low Drag Seals ...................................................................................................... 111 3.3.3 Lubrication Strategies ........................................................................................... 111 3.3.4 Advanced CV Joints ............................................................................................... 113 3.3.5 Dry Clutch Systems ............................................................................................... 113 3.4 Design ........................................................................................................................... 113 3.4.1 Hypoid Offset Optimization .................................................................................. 113 2 3.4.2 Non Serviceable Components ............................................................................... 114 3.4.3 Bearing Preload Optimization ............................................................................... 114 3.4.4 Single Shaft Power Transfer Units ........................................................................ 115 3.4.5 Propshaft Gear Ratio ............................................................................................. 115 3.5 Materials ...................................................................................................................... 116 3.5.1 Magnesium Housings ............................................................................................ 116 3.5.2 High Efficiency Lubricants ..................................................................................... 117 3.6 Manufacturing Process ................................................................................................ 117 3.6.1 Vacuum Die Casting .............................................................................................. 117 3.6.2 Hypoid Manufacturing .......................................................................................... 118 3.7 Advanced Engineering / Development Process ........................................................... 119 3.7.1 AWD Duty Cycle Management ............................................................................. 119 3.7.2 Performance Adaptation to Vehicle Variants ....................................................... 119 3.8 Advanced Operating and Control Strategies................................................................ 119 3.8.1 Disconnect strategies ............................................................................................ 119 3.9 Summary of Efficiency Improvement Potentials ......................................................... 120 4 Trend Analysis ...................................................................................................................... 122 4.1 The Baseline ................................................................................................................. 122 4.1.1 Global Vehicle Production ...................................................................................