A new technique for measuring ignition quality of diesel fuels has been evaluated. Primarily a constant volume combustion apparatus, the Diesel Fuel Ignition Analyser (DFIA) provides a direct output of ignition delay. Microprocessor control and semi-automatic operation ensure rapid determinations. Tests were performed to find the operating conditions giving the best results in terms of various performance indicators, settling upon 450°C/20bar for combustion air preheat and pressure.A preliminary correlation model based on ignition delay predicted D613 Cetane Number with ± 1.3CN at 95% confidence. More results are required to improve this correlation and define statistical precision of the method.