Light Duty Vehicle Life Cycle Analysis

The short-term future direction of the automotive transportation sector is uncertain. Many governments and environmental localities around the world are proposing internal combustion engine (ICE) bans and enacting large subsidy programs for zero-tailpipe emissions vehicles powered by batteries or fuel-cells. Such policies can be effective in driving the consumer towards specific powertrains. The reason for such aggressive change is to reduce the sector’s carbon footprint. However, it is not clear if these proposals will reduce greenhouse gas (GHG) emissions. Emissions from raw material extraction, manufacturing, and power generation are shadowed by the focus on reducing the reliance on fossil fuel use. Emissions from non-tailpipe sources should also be considered before pushing for a rapid change to powertrains. Life-cycle analysis (LCA) can assess the GHG emissions produced before, during and after the life of a vehicle in a cradle-to-grave analysis. Southwest Research Institute (SwRI) has performed an LCA study on two different light-duty vehicles and five different powertrain configurations. The first vehicle platform chosen is the compact sedan, also known as a C-segment or small family car. The second vehicle platform chosen is a standard full-size pickup truck. For each platform an internal combustion engine, mild hybrid, full hybrid, plug-in hybrid and battery electric powertrain were selected; specifications for each were based around current production vehicles, or near production vehicles. The analysis compares the impact of electrical grid carbon intensity to predict the global warming potential of various powertrain options in different markets. The results are presented by comparing embedded emissions and in-use emissions. The study concludes that while battery electric vehicles do generally show a lower life-cycle CO_2, a variety of pathways should be explored for future powertrain needs due to the variation of available low-carbon electricity and production in different markets.