TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The synthetic middle distillate is defined by the sulfur content of less than 10 ppm sulfur, the specific gravity of less than 0.8, a cetane number of greater than 70 (preferably greater than 75), a paraffin content of greater than 90 wt.%, a bromine (Br) number of less than 0.1 g Br/100g, an aromatics content of less than 1 wt.%, and a boiling range having a 5% boiling point of 170-210degreesC and a 95% boiling point of 320-350degreesC. It is derived from synthesis gas. The liquid biofuel has sulfur content of less than 30 ppm sulfur. It comprises a compound from vegetable oils, alkyl esters of vegetable oils, and/or mixtures (preferably) of alkyl esters of fatty acids; or an alkyl ester of a vegetable oil. The vegetable oil is canola oil, soybean oil, cotton oil, palm oil, and/or sunflower oil. It is preferably canola oil and/or soybean oil. The amount of liquid biofuel comprises 1-45 (preferably 1-20 or 20-45) vol.% of the diesel fuel. The liquid biofuel has a total glycerin content of less than 0.24 wt.% of glycerin, and alcohol content of less than 10 wt.%. The mixture of the synthetic middle distillate and the liquid biofuel comprises more than 90 vol.% of the synthetic diesel. The synthetic diesel fuel is a synthetic environmental-friendly diesel fuel that produces reduced sulfur and nitrogen oxide (NOx) emissions when used in compression ignition engines. The synthetic environmental-friendly diesel fuel comprises a synthetic liquid distillate defined by a cetane number of greater than 70, a sulfur content of less than 10 ppm sulfur, a paraffin content of greater than 90 wt.%, and a specific gravity of less than 0.8; and the liquid biofuel defined by a sulfur content of less than 30 ppm sulfur and a specific gravity of greater than 0.86, where the liquid biofuel is derived from a compound from vegetable oils, animal greases, vegetable oil wastes and/or micro-algae oils. The liquid biofuel is blended with the synthetic liquid fuel to form the synthetic diesel fuel. The synthetic liquid distillate is the synthetic middle distillate. Preferred Properties: The liquid biofuel has a flash point of greater than 100degreesC, and a kinematic viscosity at 40degreesC of 1.9-6 mm2/s. The synthetic diesel has a cetane number of greater than 60. EXAMPLE - A Fischer-Tropsch (FT) diesel was obtained by converting a synthesis gas stream with a hydrogen-to-carbon monoxide molar ratio of 2:1 over an FT cobalt-based catalyst in a slurry bubble reactor at 210-215degreesC and a pressure of 4-50 psig (3200 kPa) to form a hydrocarbon synthesis product. The hydrocarbon synthesis product was then hydrotreated over a nickel-based catalyst to transform all of olefins and oxygenates to paraffins, then fractionated in an atmospheric distillation column to at least obtain an FT diesel fraction. The experiment was performed to examine two separate issues with regard to fuel formulation and engine emissions. The first was to study the difference in bulk modulus between biodiesel fuels and diesel fuels and the resulting effect on fuel injection timing. The second was the investigation of the potential impact of the use of paraffinic fuels, e.g. FT diesel fuels, on injection timing. Blends of 20% and 40 vol.% of (methyl soy) biodiesel and the FT diesel thus displayed a lower bulk modulus of compressibility than the baseline diesel fuel, and generated lower NOx emissions than the baseline diesel.