Selection of lightweighting strategies for use across an automaker´s vehicle fleet

Vehicle lightweighting, or mass reduction, via materials substitution is a common approach to improve fuel economy. The many subsystems in a vehicle, choices of materials, and manufacturing processes available, though, lead to numerous paths to achieving the mass reduction and identifying the best ones for an automaker to implement can be a challenge. In this paper, that challenge is addressed through the development of a selection model designed to inform the lightweighting strategy decision for an automaker´s fleet. The model, implemented with a genetic algorithm, identifies the strategies that enable an automaker to optimize the net present value of its cash flow, as well as to meet its CAFE obligations over the coming years. A case study of various strategies implemented in three vehicles over a three-year timeframe is used to demonstrate application of the genetic algorithm selection model and contrast it to an alternative period-by-period search implementation.