Variable fuel vehicles

Fig. 4. Components of a Lumina methanol variable fueled vehicle (VFV).

Initially, at least, methanol vehicles should be capable of operating on either M85, gasoline, or any mixture of the two. These vehicles are caHed flexible fueled (EEV) or variable fueled vehicles (VEV). It is expected that methanol could be sold in existing service stations out of tanks constmcted of methanol-tolerant material such as carbon steel or certain fiber glass formulations. EventuaHy, if enough EEV/VEVs are sold and methanol becomes widely avaHable, dedicated vehicles would likely be buHt and sold. Methanol has been used for years as a racing fuel. 

Technological changes in the manufacture of power sources are required if they are to run on alternative fuels. The development of alternative fuels depends on automotive manufacturers making alternative fuel engines available while fuel suppliers produce and distribute fuels for these vehicles. Flexible fuel vehicles (FFVs), which are also known as variable fuel vehicles, (VFVs) are designed to use several fuels. Most of the major automobile manufacturers have developed FFV prototypes and many of these use ethanol or methanol as well as gasoline. 

When ethanol is used in a standard spark ignition or compression ignition engine designed to bum conventional hydrocarbon-based fuels, ethanol performance varies substantially if no engine modifications are made, and it becomes difficult to rate the value of ethanol as an effective fuel. Consequently, flexible fueled vehicles (FFVs) or variable fueled vehicles (VFVs) have been developed to operate on either gasoline or alcohol-based fuels. These vehicles are equipped with on-board sensors and controls to adjust the spark advance and the fuel injector timing to help correct for the differences in fuel performance. 

Benson, J.D., et al., Emissions with E85 and Gasolines in Flexible/ Variable Fuel Vehicles—The Auto/Oil Air Quality Improvement Research Program, SAE Paper No. 952508, Society of Automotive Engineers, Warrendale, Pa., 1995. 

The preliminary results reported are based only on exhaust emissions and do not include the evaporative emissions which are a major source of vehicle emissions. The results from evaporative emissions and from the flexible and variable fuels vehicles testing with meAanol-containing fuels will be released sometime this year. 

In most cases the ethanol is blended with gasoline. The vast majority of cars and trucks can use a 10% blend with gasoline (E10) in USA. A 22% blend of ethanol with gasoline (E22) is the most sold fuel in Brazil. Flex-fuel vehicles (FFV) are capable of running on variable blends up to 85% bioethanol (E85). However, when using E85 the fuel consumption increases by 20-30% due to differences in energy per unit volume. 

The behavior of these pollution roses is intuitively plausible, because considerable hydrocarbon emissions come from motor vehicles which are operated in both winter and summer and travel throughout the urban area. On the other hand, sulfur dioxide is released largely from the burning of coal and fuel oil. Space heating emissions are high in winter and low in summer. The SO2 emissions in summer are probably due to only a few point sources, such as power plants, and result in low average concentrations from each direction as well as large directional variability. 

In earlier times it was customai y to eliminate vehicle velocity as a variable by measuring fuel ecotiomy while driving at a constant speed, typically 40 mph. Fuel economy at this speed generally falls within 10 percent of its maximum level-road value. Fuel economy falls off at both much lower and much higher speeds. 

It is essential to collect sales figures and the associated costs by the day/week/month, and to separate the figures for the different products. It is also essential to distinguish between fixed and variable costs. As we have seen (Chapter 8), the latter include costs such as field preparation, seed, harvesting and packaging. Fixed, or overhead, costs include loan repayments, property taxes, insurance, depreciation and maintenance on buildings and equipment. It is important to include the farmer s salary as a fixed cost, as well as marketing costs, deliveries, fuel, and vehicle upkeep. 

For most chemical storage tanks, codes such as NFPA 30 and the International Fire Code give specific separation distances. For motor vehicle fueling applications, the codes are more stringent on separation requirements due to a greater exposure of the public to the hazards. Hence codes such as NFPA 30A establish variable separation distances depending upon whether the facility is private or pubhc. 

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