High speed diesel engines are difficult to start in cold conditions (at subzero temperature) because the cylinder head and cylinder block absorbs heat of compression and thus preventing ignition due to the high surface to volume ratio. Also the coolant and the engine oil become viscous at subzero temperature and make the condition unfavorable for starting. Combustion optimization along with the help of a heating aid can make these engines to start quickly without any engine misbehavior.Cold startability is the ability of an engine to start within a specified time and continue to run without any malfunctioning. Combustion instability will lead to the misfiring of the engine unless it is calibrated properly. The European countries are subjected to a minimum temperature of -20°C to -25°C. So the intention of this work is to optimize the cold startability of Mahindra's Multi-Purpose Vehicle (MPV) up to -25°C which is to be sold in European countries.For this purpose, experiments were conducted on this MPV having a 2.2L common rail direct injection diesel engine. In order to enhance the startability, individual glow plugs have been used in each cylinder. The vehicle had been prepared and put in a cold chamber where the ambient temperature can be brought down to -30°C. The temperature had been varied from 10°C to -25°C in steps of 5°C.At each temperature, the startability was checked and optimized to get the best results in terms of startability, stability in idle and smoke behavior. The possibility of introducing the multiple injections has also been studied. The combustion optimization with the help of starting aid helped the engine to start very quickly even at -25°C.