Future vehicle types and characteristics : reducing fuel consumption through shifts in vehicle segments and operating characteristics
Author(s)Perlman, David (David Lee)
Reducing fuel consumption through shifts in vehicle segments and operating characteristics
Massachusetts Institute of Technology. Technology and Policy Program.
John B. Heywood.
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Light duty vehicles represent a notable target of regulation in the United States due to their environmental, safety, and economic externalities. Fuel economy regulation represents one of the more prominent attempts to limit the environmental externalities of passenger vehicles entering the U.S. fleet, but focus intently on technology improvements rather than encouraging the sale of more fuel-efficient vehicle segments. More precisely, the current fuel economy standards, which will be phased in between 2012 and 2025, reflect an approach that is explicitly intended to be neutral with regard to the size and types of vehicles sold, with the stringency of the standard scaled to vehicle footprint, or the area between the four wheels. In light of this size-neutral approach to fuel economy regulation, as well as a lack of precedent in the automotive literature, the author examined the extent to which shifts in demand for different light duty vehicle segments can impact fleet-wide LDV fuel demand. Shifts in the demand for LDV segments have occurred in recent decades, with the market share of conventional passenger cars decreasing from more than 80 percent in the early 1980s to just over half today, replaced largely by sport utility vehicles (SUVs) and crossover utility vehicles (CUVs). Though many factors influenced this transition away from conventional passenger cars, available literature suggests that misalignment between fuel economy policy and prevailing market conditions, combined with some protectionist tax policies for the domestic auto industry, were the main culprits. Moreover, a fleet model analysis suggests that the impact in terms of fleet-wide fuel consumption was not trivial, with vehicles sold between 1985 and 2010 consuming, over their entire useful life, over 100 billion gallons of petroleum more than if 1985 LDV market segments have prevailed over that period. This historical analysis provided motivation and justification for exploring the potential for shifts between segments in the LDV market to influence LDV petroleum demand over the next several decades, in order to illustrate the potential missed opportunities of implementing fuel economy regulations that do not encourage the sale of smaller, more fuel-efficient vehicle segments. Using a spreadsheet-based accounting model of the vehicle fleet, the author's analysis suggests that plausible shifts in the market shares of different LDV segments could increase or decrease LDV petroleum demand by up to seven percent, relative to a reference case provided by the U.S. Energy Information Administration (which, in itself, suggests a modest decrease in the demand for SUVs and CUVs through 2040). The author also explored the potential of a more radical -yet still plausible - change to LDVs to impact fleet-wide fuel consumption over the next few decades. Automating passenger vehicle controls has long been imagined by futurists and tested in various forms by automotive manufacturers since the 1950s, but recent developments stemming from a series of competitions sponsored by the Defense Advanced Research Projects Agency between 2007 and 2011 suggest that increasingly automated vehicle features may soon become a production reality. Though intended primarily as a means of improving safety, automated vehicle systems have the potential to also decrease fuel consumption. Also using the fleet model, the author evaluated the potential of a highway-only partial automation system - akin to systems reportedly being introduced to the market by General Motors and Tesla, among others, within the next two years - to reduce fleetwide LDV fuel consumption. Results suggest that, depending on a wide range of variables, reductions in fleet-wide fuel consumption of up to two percent are possible by 2050 relative to the Energy Information Administration reference case. Though the results of the analysis explored in this thesis may seem modest, they are notable nonetheless. Most importantly, they represent reductions in fuel consumption that are possible to achieve in addition to those likely to be driven by current fuel economy regulations. Therefore, the changes to passenger vehicles explored in this thesis represent potential strategies for reducing LDV fuel consumption as manufacturers reach the limits of technological improvements to engines.
Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2015."June 2015." Cataloged from PDF version of thesis.Includes bibliographical references (pages 91-96).
DepartmentMassachusetts Institute of Technology. Engineering Systems Division.; Massachusetts Institute of Technology. Technology and Policy Program.
Massachusetts Institute of Technology
Engineering Systems Division., Technology and Policy Program.