Automobile engines fuel economy

Eor a considerable period, >90% of the new cars in Brazil operated on E96 fuel, or a mixture of 96% ethanol and 4% water (82). The engines have high compression ratios (ca 12 1) to utilize the high knock resistance of ethanol and deUver optimum fuel economy. In 1989 more than one-third of Brazil s 10 million automobiles operated on 96% ethanol/4% water fuel. The remainder ran on gasoline blends containing up to 20% ethanol (5). 

It should also be mentioned that low oil viscosity at low temperatures is desirable in the new small 4 cylinder and V-6 cylinder fuel economy automobiles ( 5, 6). This is to permit sufficient speed of engine cranking for cold weather starting at winter temperatures. Low oil volatility must be maintained to prevent oil misting and blowby from poisoning the catalyst system and oxygen sensors in the anti-pollution devices (7). 

A hydrogen economy will require the expenditure of hundreds of billions of dollars to build an entirely new energy infrastructure (pipelines, fueling stations, automobile engines). This will come from public and private money. 

There is currently a great interest in improving automobile fuel economy and to reduce emissions of carbon dioxide into the atmosphere. One step in this direction is to use a technique where a gasoline engine is operated at lean-bum conditions. Using this concept it is possible to improve fuel economy significantly [1,2] compared to the normal stoichiometric operation. A setback with lean-bum technology is that Ae common three-way catalyst is... 

The relaxation of the 1975 Federal standards had various impacts on the automobile manufacturers who had been proceeding with plans for the use of catalysts in 1975 in the event that it was necessary to meet the tight standards. Some large manufacturers proceeded to use catalysts extensively, while optimizing the engine calibrations to allow substantial improvements in fuel economy (12-28%) over the 1974 models (31). One chose... 

Polypropylene, a homopolymer polyolefin engineering plastic provides excellent chemical resistance, purity and it is the lightest of all commercial plastics. PP offers innovative solutions to many challenges that face the automotive industry today. Its low density compared to traditional materials significantly contributes to fuel economy and reduced material costs. Its excellent noise, vibration, and harshness (NVH) properties contribute to enhanced passenger comfort. Thus, PP has become the most important thermoplastic material in automobile industry. PP homopolymers, random copolymers, and impact copolymers are used in products such as automotive parts and battery cases, carpeting, electrical insulation, and fabrics. 

Buses require more power than passenger automobiles, typically about 250 kW or more. They operate in a more demanding operating regimen with frequent starts and stops. Nevertheless, the average fuel economy of a bus fuel cell system is roughly 15% better than that of a diesel engine [24]. 

Transportation accounts for about one-fourth of the primary energy consumption in the United States. And unlike other sectors of the economy that can easily switch to cleaner natural gas or electricity, automobiles, trucks, nonroad vehicles, and buses are powered by internal-combustion engines burning petroleum products that produce carbon dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons. Efforts are under way to accelerate the introduction of electric, fuel-cell, and hybrid (electric and fuel) vehicles to replace sonic of these vehicles in both the retail marketplace and in commercial, government, public transit, and private fleets. These vehicles dramatically reduce harmful pollutants and reduce carbon dioxide emissions by as much as 50 percent or more compared to gasoline-powered vehicles. 

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