We developed a scale-up model of a previously reported alternative diesel fuel production plant and evaluated the characteristics of the fuel produced. For this plant, two reactors with internal diameters (I.D.s) of 8mm and 14mm, were constructed and evaluated. Our research showed that the 8mm I.D. reactor offered better performance in terms of reaction velocity than the 14mm I.D. reactor, and that the composition of the fuel produced in the 8mm I.D. reactor was nearly identical to that produced by our first small-scale test plant. We then evaluated fuel production at several reaction temperatures. The results of these evaluations showed that the reaction rate of thermal cracking increased at higher reaction temperatures, consequently improving the kinetic viscosity, pour point, iodine value and other physical characteristics of the fuel. However, it was also found that the overall fuel quality was affected by the quality of the material oils used in our plant and, as a result, it is essential to employ a suitable reaction temperature when using low-quality waste edible oils.