Search Results

Federal standards that mandate improved fuel economy have resulted in the increased use of lightweight materials in automotive applications. However, the environmental burdens associated with a product extend well beyond the use phase. Life cycle assessment is the science of determining the environmental burdens associated with the entire life cycle of a given product from cradle-to-grave. This report documents the environmental burdens associated with every phase of the life cycle of two fuel tanks utilized in full-sized 1996 GM vans. These vans are manufactured in two configurations, one which utilizes a steel fuel tank, and the other a multi-layered plastic fuel tank consisting primarily of high density polyethylene (HDPE). This study was a collaborative effort between GM and the University of Michigan's National Pollution Prevention Center, which received funding from EPA's National Risk Management Research Laboratory.

The life cycle design framework developed at the University of Michigan was applied by AlliedSignal to improve the manufacture, use, and end-of-life management of automobile oil filters. Three oil filter designs were investigated: a conventional spin-on filter which is a single-use product, a cartridge filter consisting of a reusable housing and a replacement cartridge, and a cleanable design which uses a reusable housing and cleanable filter element. Environmental, cost, performance, and legal requirements were developed using a matrix tool and tradeoffs between these requirements were studied. These design criteria are presented along with results from an analysis of user life cycle costs and a simplified life cycle energy analysis. Key elements of the life cycle design framework, which is based on systems analysis, multiobjective analysis, and multistakeholder participation, are also described.

The U.S. EPA initiated the Common Sense Initiative (CSI) to develop “Cleaner, Cheaper, Smarter” environmental policy and management practices. This paper addresses the application of life cycle design and assessment tools to automotive instrument panels (IP) as part of the Automotive Manufacturing Sector CSI pilot project investigation. For this study, an “average IP” was modeled based on the instrument panels of three mid-sized U.S. car models: 1995 Chevrolet Lumina, 1996 Dodge Intrepid and 1996 Ford Taurus. This “average IP” consisted of seventeen different materials and weighed over 22 kg (49 lbs.). A life cycle inventory analysis was conducted to evaluate the environmental burdens associated with materials production, manufacturing, use, and retirement. A thorough evaluation of solid waste production and energy consumption was completed and partial inventories of air emission and water effluent releases were also conducted.

In 1998 the United States Automotive Materials Partnership published the life cycle inventory of a generic US family sedan. Several years later, researchers at the University of Michigan expanded this analysis to consider the dynamic replacement decisions over the vehicle lifetime that would optimize energy and emissions performance of generic family sedan ownership. The present study provides further analysis of this vehicle by examining the life cycle cost profile for generic sedan ownership and determining the optimal replacement intervals for this vehicle based on economics. Life cycle cost for a generic vehicle was estimated as $0.37/mile for a ten year life cycle and $0.31/mile for a twenty year life cycle. This study found that while less than 10% of the generic vehicle life cycle energy (20 year) is consumed during material production and manufacturing, 43% of the total life cycle cost is associated with vehicle purchase and depreciation.

A novel application in the field of Life Cycle Assessment is presented that investigates optimal vehicle retirement timing and design life. This study integrates Life Cycle Energy Analysis (LCEA) with Dynamic Replacement Modeling and quantifies the energy tradeoffs between operating an older vehicle versus replacing it with a new more energy efficient model. The decision to keep or replace a vehicle to minimizes life cycle energy consumption is influenced by several factors including vehicle production energy, current vehicle's fuel economy and its deterioration with age, the improvement in fuel economy technology of new model vehicles and annual vehicle miles traveled (VMT). Model simulations explore vehicle replacement under incremental improvements in vehicle technology and leapfrog technology improvements such as with the PNGV (Partnership for a New Generation of Vehicles).