SPONSORED BY CUMMINS ENGINE CO.
Winter may seem like a long time away right now but Fall is right around the corner. That is the time to begin preparing your vehicles for colder temperatures to ensure that they’re ready for what winter has in store. Below is a checklist of items for which bus fleet operators need to be proactive to prepare for extreme conditions, whether you are running diesel or natural gas engines. These procedures, ranging from cooling system maintenance to fuel choice, to selecting the right engine oil, will help fleets keep their buses running safely and reliably in cooler ambient temperatures.
Cold-weather preparation/operation procedures for Cummins Westport natural gas engines are similar to those for diesel engines (block heater, coolant heater, battery warmer, radiator shutters or winter fronts, etc.). CNG filling stations should include a dryer to remove moisture from the natural gas.
Dry fuel is an important consideration for cold-weather operations. It is important to consider minimizing load on the engine at start by turning off Power Take-Off (PTO) accessories such as hydraulic pumps, etc.
Natural gas fuel systems include a pressure regulator that is kept from freezing with a supply of warm engine coolant. In cold weather, allow the engine to warm to operating temperature before operating under load. Maintain intake air temperatures above freezing through the use of winter fronts and/or warm underhood air. The correct engine coolant, lubricating oil, and fuels must be used for the cold-weather range in which the engine is being operated:
Ambient Temperature 32°F to -25°F (0 to -32°C) – Use 50 percent ethylene glycol antifreeze and 50 percent water for the engine coolant mixture.
Ambient Temperature -25°F to -65°F (-32 to -54°C) – Use 60 percent ethylene glycol antifreeze and 40 percent water for the engine coolant mixture. Refer to Section V (Lubricating Oil Recommendations) of your Owners Manual for correct specifications.