Vehicle performance

We believe to have shown here that the RVP of gasoline is a primary characteristic for quality resulting from a delicate compromise between the demands for vehicle performance, optimization of refinery operations and environmental protection. 

The factory-produced, dedicated NGV is the ultimate goal of the NGV industry because it will reduce the incremental cost of the vehicle, the fuel system will be belter integrated into the vehicle, and the vehicle performance can be optimized for natural gas. A dedicated NGV s emissions, power, and driveability can be superior to a comparable gasoline vehicle. There is however, a reluctance by some automobile manufacturers to produce dedicated NGVs until the refueling infrastructure is more fully developed. 

Several different metrics are used to assess vehicle performance. Included are the time required to travel a specified distance from a standing start, the time required to accelerate from rest or from some initial speed to a specified final speed, and the speed that can be maintained on a specified upgrade without downshifting the transmission from its highest gear. In the United States, the most frequently used metric of this nature is the time required to reach 60 nipli from a standing start. 

Vehicle data represents the complex interaction of many variables, including vehicle performance, reactor design and location, as well as catalyst properties. For a catalyst that has failed, one must ponder whether the converter design used in the vehicle is suitable for the catalyst, the quantity of the catalyst used is correct, the distance of the converter from the exhaust manifold is suitable, the catalyst has been inadvertantly overheated to above 2000°F or poisoned by lead and sulfur, or whether the catalyst can be modified to produce a far superior product. 

A critical safety issue of using diesel-ethanol blends relates to flashpoint and flammability. E-diesel blends containing 10-15% ethanol have the vapor pressure and flammability limits of ethanol. This means that ethanol concentrations in enclosed spaces such as fuel storage and vehicle fuel tanks are flammable over the temperature range 13-42 °C. Thus, there are higher risks of fire and explosion than with diesel fuel, or even gasoline. Other vehicle performance-related concerns are (a) a decreased maximum power (b) an increased incidence of fuel pump vapor lock and (c) a reduced fuel pump and fuel injector life due to the decreased lubricity of ethanol. 

The two fuel vehicles began operation late in the summer of 2007. Users maintain logs that document vehicle performance, and tests are ongoing to evaluate the operational experience and the refueling station. Other NREL evaluation projects involve transit buses powered by fuel cell hybrids in Oakland, California, Thousand Palms, California, and Hartford, Connecticut. 

This chapter explains what alternative fuels are and why they are being considered for use in transportation vehicles. The production processes to make each are presented along with examples of recent production volumes. The typical impacts on vehicle performance (power, driveability, cold-start capability, etc.) are presented as well as typical vehicle emissions characteristics. 

Only experimental hydrogen vehicles have been built to date, and it is not possible to derive meaningful conclusions about vehicle performance characteristics from them. Based on the internal-combustion engine work conducted to date,... 

The properties of a fuel define its physical and chemical characteristics. A thorough understanding of the properties of a fuel is essential to the design and engineering of engine combustion systems, vehicle fuel systems, fuel storage, and fuel dispensing systems. Fuel properties impact vehicle performance, emissions, fuel efficiency, reliability, and durability. 

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