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Amory B. Lovins, CEO of RMI, submits comments to NHTSA challenging the technical basis of its proposed rulemaking on automobile fuel economy standards. He argues that NHTSA incorrectly relies on retrospective correlations between vehicle weight and safety, which fail to account for modern materials like advanced polymer composites and high-strength steels. Lovins asserts that these materials can create vehicles that are simultaneously large, lightweight, and safe, thereby eliminating the perceived tradeoff between fuel economy and crashworthiness. He recommends that CAFE standards be performance-based, technology-forcing, and based on size metrics rather than mass to avoid incentivizing a 'mass arms race' and to maintain the global competitiveness of U.S. automakers.

The report argues that California can significantly reduce its global warming impact by mandating the adoption of existing and near-term vehicle technologies. Modeling shows that currently available improvements in engines, transmissions, and air conditioning could reduce fleet average heat-trapping emissions by 20%, while advanced technologies available within five years could achieve a 40% reduction. These improvements are presented as cost-effective, with fuel savings offsetting initial costs within a few years, and would provide a model for other U.S. states and Canada.

The report compares conventional, advanced, and hybrid-electric diesel and gasoline vehicles across five passenger vehicle classes. It finds that while diesel engines offer higher inherent fuel economy, they are less cost-effective than improved gasoline vehicles for reducing oil use and heat-trapping gases due to higher up-front costs and the higher petroleum intensity of diesel fuel. The report also highlights significant public health concerns, noting that diesel vehicles historically emit substantially more toxic soot and nitrogen oxides than gasoline vehicles. While new federal Tier 2 standards aim to close this gap, the report argues that diesel's future depends on overcoming technical challenges in emissions control and ensuring real-world performance matches certification. It recommends maintaining strict emissions standards, modifying CAFE to use energy-equivalent measures, and expanding inspection and maintenance programs to include diesel vehicles.

The Union of Concerned Scientists report 'A Blueprint for Saving Lives, Money, and Gasoline' analyzes the safety and environmental shortcomings of SUVs and light trucks in the United States. It highlights high rollover fatality rates, significant air pollution, and poor fuel economy compared to passenger cars. To demonstrate potential improvements, the authors propose two model vehicles—the UCS Guardian and the UCS Guardian XSE—which utilize existing technologies such as unibody construction, advanced engines, and electronic stability control to increase fuel efficiency and reduce fatalities without sacrificing vehicle size or performance.

The report argues that hybrid electric vehicles (HEVs) can bridge the gap between current conventional vehicle technology and the long-term adoption of hydrogen fuel cells. It categorizes hybrids into mild, full, and plug-in types based on technological steps like regenerative braking and electric-only drive. Modeling suggests a passenger fleet using advanced full hybrids could reach an average of 60 mpg, significantly reducing oil consumption and greenhouse gas emissions while remaining cost-effective for consumers over the vehicle's lifetime.

The report evaluates the emissions of US school bus fleets, finding that the vast majority rely on high-polluting diesel engines that pose significant health risks to children. It advocates for a transition to cleaner alternatives, specifically natural gas, and calls for federal and state funding to replace aging fleets.

The report argues that the US can significantly reduce its oil consumption and environmental footprint by aggressively raising Corporate Average Fuel Economy (CAFE) standards. It proposes a path to 40 mpg by 2012 and 55 mpg by 2020 using evolutionary conventional technologies and hybrid electric vehicles. The analysis suggests these improvements would save consumers billions of dollars, create over 100,000 automobile industry jobs by 2020, and reduce greenhouse gas emissions by 888 million tons by 2020. Furthermore, the report contends that these fuel savings would far exceed the potential oil supply from the Arctic National Wildlife Refuge and that safety can be maintained or improved through better design and the reduction of weight disparity between light trucks and passenger cars.

The report argues that while diesel trucks and buses are essential for commerce, they are disproportionate sources of smog, soot, and greenhouse gases. It evaluates a transition from conventional diesel to a 'green truck path' involving advanced exhaust controls, natural gas, hybrids, and fuel cells. The authors model a 2030 scenario where aggressive policies could reduce pollutant emissions by over 90% and global warming pollutants by 26%, while maintaining current oil consumption levels despite doubling truck travel.

The Hypercar concept, developed by the Rocky Mountain Institute (RMI), proposes a 'whole-system' approach to vehicle design to achieve fuel economies of 90 to 200 mpg. This is accomplished through the synergy of advanced polymeric composites to reduce mass by 50-65%, aerodynamic improvements to cut drag by 40-50%, and hybrid-electric drivesystems that recover up to 50% of braking energy. The document asserts that these vehicles can maintain safety standards, including in collisions with heavier cars, and could be compatible with various fuels, including hydrogen via fuel cells. RMI estimates that production-volume Hypercars could appear in the early 2000s, with costs comparable to conventional vehicles.

The report challenges claims by the American Automobile Manufacturers Association (AAMA) that modern cars are 90-96% cleaner than 1960s precontrol cars. It finds that real-world emissions are significantly higher than regulatory standards due to equipment malfunction and 'off-cycle' driving. Furthermore, a 2.7-fold increase in total vehicle miles traveled and a shift toward light trucks—which have less stringent standards—have offset per-vehicle gains. Consequently, while hydrocarbons decreased, nitrogen oxide emissions for the total passenger fleet actually increased by over 20% between 1965 and 1995. The author concludes that passenger vehicles remain a primary source of carbon monoxide and smog-forming pollutants, necessitating a shift toward intrinsically-clean vehicle technologies.

The document proposes the "hypercar" concept, which utilizes a recursive "mass decompounding" process to create ultralight vehicles. By combining advanced composites and hybrid-electric drives, the authors argue that cars can achieve significantly higher fuel economy and lower emissions without sacrificing performance or cost. The paper examines the lifecycle benefits of this approach, including reduced embodied energy in manufacturing, lower in-use emissions, and the potential for high-value recycling of polymer composites through processes like low-temperature catalytic pyrolysis.

The paper presents a technical case for 'ultralight hybrid vehicles' (UHVs), asserting that fuel efficiency can be improved 3–4x over conventional cars without compromising marketability. It emphasizes that reducing tractive loads—through mass reduction, aerodynamic optimization, and low-rolling-resistance tires—is the most critical factor in making hybrid drivesystems cost-effective. Using the SIMPLEV model, the author demonstrates a design with a curb mass of 585 kg and a drag coefficient of 0.19 that achieves high fuel economy (up to 115 mpg on highways) and low emissions, while meeting strict performance criteria for acceleration and gradability.

The paper argues that achieving tripled fuel economy requires a systems-optimization approach rather than incremental improvements. It proposes a combination of carbon-fiber composite body-in-white structures, low-drag aerodynamics, and series hybrid-electric propulsion. Modeling suggests that such a 'leapfrog' approach can yield vehicles achieving 80-100+ mpg while maintaining family-sedan utility and safety.

The report proposes the 'Hypercar', an ultralight hybrid-electric vehicle that combines synthetic composite materials with hybrid propulsion to increase fuel efficiency by up to ten times compared to standard cars. It argues that the current 'Iron Age' approach of incremental steel-car refinements is obsolete and that the U.S. must transition to agile, low-capital manufacturing using moldable composites to maintain global competitiveness. The authors suggest that government mandates, such as California's ZEV requirements, and market-based 'feebates' can accelerate this transition, which would reduce oil dependency and environmental impact while fostering industrial renewal.

The paper proposes replacing conventional steel cars with 'supercars' that combine ultralight composite bodies, aerodynamic optimization, and hybrid-electric powertrains. The authors argue that such vehicles could achieve fuel efficiencies of <1.6 litres per 100 km in the near term and 0.8-1.0 litres per 100 km ultimately, without sacrificing safety or performance. This transition would require a shift from capital-intensive steel stamping to flexible, low-tooling composite moulding and a move toward direct-to-consumer marketing, potentially disrupting the existing industrial structure of the global auto industry.

The document highlights the environmental and safety risks associated with the global trade of used vehicles, noting that between 2015 and 2018, 14 million light used vehicles were exported, with 80% going to low- and middle-income countries and over half to Africa. It asserts that vehicles with weak import regulations correlate with higher traffic mortality rates and contribute significantly to urban air pollution through PM2.5 and NOx emissions. The text calls for developed nations to stop exporting vehicles that fail environmental and safety inspections and for importing nations to adopt stricter quality standards to facilitate the acquisition of cleaner, safer fleets, including hybrid and electric options.

The document details a proof of concept (POC) conducted by Octotel and KepuGas in Cape Town to evaluate LPG as an alternative fuel for light delivery vehicles. Testing on a Nissan NP200 and a Fiat Fiorino demonstrated significant cost savings (between 39.8% and 44.2%) and a reduction in emissions, specifically an estimated 22% decrease in CO2 and 68% decrease in NOx compared to petrol. The study highlights LPG's potential as a transition fuel toward full decarbonisation, noting its safety, lower maintenance costs due to reduced carbon build-up, and the ability for fleet owners to claim VAT.

The text proposes the 'Hypercar' as a solution to the inefficiencies and environmental damage of the traditional steel-based automobile industry. By combining ultralight composite materials, low-drag design, and hybrid-electric propulsion (specifically hydrogen fuel cells), Hypercars could drastically reduce fuel consumption and emissions. However, the author emphasizes that technological efficiency alone cannot solve traffic congestion or urban sprawl, necessitating a shift toward 'New Urbanist' design, market-based parking costs, and improved community planning to reduce the necessity of car travel.

The Rocky Mountain Institute (RMI) conducted a life cycle analysis (LCA) using the Argonne National Laboratories' GREET model to evaluate the environmental impacts of the Toyota Prius and the Hummer H3. RMI tested four scenarios, manipulating vehicle lifespan and assembly energy requirements to see if the conclusions of a CNW Research/Marketing report—which claimed the Prius was more harmful to the environment—could be replicated. RMI found that the Prius consistently has a lower environmental impact in terms of greenhouse gas emissions and energy consumption, regardless of whether assembly energy for the Prius was tripled or if the Hummer was assigned a longer lifespan (207,000 miles) compared to the Prius (109,000 miles). The report concludes that vehicle operation dominates emissions due to the Hummer's poor fuel economy, and that the CNW findings diverge significantly from scientifically reviewed work.

The paper examines the barriers preventing the automotive industry from adopting advanced composite materials in the body-in-white (BIW) and proposes a "leapfrog" strategy. Instead of incremental component substitution, the authors advocate for a clean-sheet, all-composite monocoque design. This approach is presented as essential for the "hypercar" concept, where extreme mass reduction creates synergies with hybrid-electric drivetrains, reducing the size and cost of propulsion systems. The document analyzes various manufacturing technologies, such as resin transfer molding (RTM) and E-beam curing, and argues that the high cost of carbon fiber can be offset by significant mass reductions and reduced assembly complexity. It concludes that the primary obstacles are cultural inertia and a lack of familiarity among automakers rather than intractable technical limits.