A general kinetic model which describes the combustion characteristics of aliphatic hydrocarbons at any given temperature, involving the variations of conversion, carbon number and combustion time was developed for the combustion of aliphatic hydrocarbons. A combustion quality tester (CQT) was designed, fabricated, and then used to carry out combustion experiments on CNG. Data was sourced from coherent works from the internet, for certain experiments that could not be carried out due to required equipment sophistication. Experimental data on CNG combustion were curve-fitted using the derived kinetic models to ascertain their goodness of fit. It was found that the curves fitted well at 97.5%, 97.9%, 97.6% and 98.7% goodness of fit for combustion temperatures of 385K, 390K, 395K and 400K respectively. The models agree vehemently with experimental data, and show that reaction rate of the fuel increases with temperature, and the overall reaction rate with temperature is an inverse function of combustion time. Next, ignition quality tester (IQT) was used to investigate pressure and temperature effects on ignition delay, effect of fuel additive (2-EHN) on cetane number and ignition delay, and also measurement of cetane number according to ASTM D6890 standards. Test was conducted under steady state conditions at constant pressure and temperature of 145psi and 828K respectively for cetane number experiments. Data were curve-fitted at 98.18%, 99.64%, 99.43% 99.82% and 99.19% goodness of fit for cetane number-%additive vol., cetane number-ignition delay, ignition delay-%additive vol., ignition delay-pressure and ignition delay-temperature experiments. Data agreed well with derived models. Ignition delay time of the fuel gives an inverse function with temperature, pressure, cetane number and percentage vol. additive concentration. Fuel additive (2-EHN) has a profound impact on cetane number and increases it up to about 8 points beyond which there is no appreciable increase no matter the volume of additive added. The present research finding can find use in combustion laboratories and automotive industries, to correlate certain variable parameters instead of habitually resorting to experiments.