While gasoline has a relatively high heat of combustion and a very low viscosity, both of which are positive attributes for blending, the cetane value is very low. Consequently, it was decided that gasoline would not be part of our formulations even though there have been some reports in literature indicating benefits when kept below 10% in a blended diesel fuel [42,43]. Ethanol blended into diesel fuels has also been reported to have some performance and emission benefits [28,44,45]. However, it too significantly lowers the cetane value. Our own research experience with using ethanol as fuel component in our on road vehicle testing resulted in vapor lock when the fuel temperature reached 52 C. Ethanol could
likely be used effectively in colder climates, but in the interest of keeping the array of possible blend components consistent among all created blends for this study, it was not used. Kerosene, also known as #1 diesel, has a lower viscosity than diesel fuel, while still maintaining an acceptable cetane rating. Therefore, it was used as a significant blend component. Based on this information, the guidelines or parameters set for our blended fuels in terms of
energy content required them to be created from WVO, diesel and kerosene while maximizing the amount of oil in the fuel. Diesel, WVO, and kerosene all have relatively high cetane values, which minimized the concern for evaluating or knowing the exact cetane value of each blended fuel.