Factor of Two: Halving the Fuel Consumption of New U.S. Automobiles by 2035

Abstract

This thesis examines the vehicle design and sales mix changes necessary to double the average fuel economy of new U.S. cars and light-trucks by model year 2035. To achieve this factor of two target, three technology options that are available and can be implemented on a large scale are evaluated: (1) channeling future vehicle technical efficiency improvements to reducing fuel consumption rather than improving vehicle performance, (2) increasing the market share of diesel, turbocharged gasoline and hybrid electric gasoline propulsion systems, and (3) reducing vehicle weight and size.The illustrative scenarios demonstrate the challenges of this factor-of-two improvement --major changes in all these three options would need to be implemented before the target is met. Over the next three decades, consumers will have to accept little further improvements in acceleration performance, a large fraction of new light-duty vehicles sold must be propelled by alternative powertrains, and vehicle weight must be reduced by 20-35% from today. The additional cost of achieving this factor-of-two target would be about 20% more than a baseline scenario where fuel consumption does not change from today's values, although these additional costs would be recouped within 4 to 5 years from the resulting fuel savings.Thus, while it is technically feasible to halve the fuel consumption of new vehicles in 2035, aggressive changes are needed and additional costs will be incurred. Results from this study imply that continuing the current trend of ever increasing performance and size will have to be reversed if significantly lower vehicle fuel consumption is to be achieved.

Transport Outlook 2008

“…Further improvements, up to 50% by 2050, are feasible but require through technological improvements that include battery and hybrid elements. For the USA, Cheah et al (2007) viii find similar orders of magnitude for improved fuel economy (keeping vehicle quality constant).…”

A Study of Lightweight Door Hinges of Commercial Vehicles Using Aluminum Instead of Steel for Sustainable Transportation

“…As well as being lightweight, the requirements of lower energy consumption, high recyclability, and easy manufacturability, aluminum usage in vehicles has been growing in the last decade. Cheah et al [7] investigated the effects of the material on the weight of the vehicle. By replacing cast iron components with aluminum, vehicle weight could be decreased by up to 600 kg.…”

A Case Study: Designing for Sustainability and Reliability in an Automotive Seat Structure

“…It is a technique to reduce the mass of an entire structure and its single elements while increasing the functional quality. Cheah et al [15], Lutsey [16], Witik et al [17] stated that reductions in weight can be achieved by a combination of (i) material substitution, in which conventional materials in automotive engineering such as steel, plastic and iron are replaced with lighter and special alternatives such as aluminum, magnesium, high strength steel and composite, (ii) innovative design where parts are optimized via computer-based programs and optimization techniques to achieve higher performance and (iii) vehicle downsizing.…”