2005 Dodge Ram 2500 Pickup Owner Manual Diesel - Page 233

STARTING AND OPERATING 233 Arctic Operation Where there are no provisions to keep the engine warm when it is operating in ambient temperatures consistently below (-10°F/-23°C), use 5W-40 synthetic engine oil and fuel that meets the requirements in Section 7, "Maintenance Procedures," Engine Oil Selection. Engine Warm-Up Avoid full throttle operation when the engine is cold. When starting a cold engine, bring the engine up to operating speed slowly to allow the oil pressure to stabilize as the engine warms up. NOTE: High-speed, no-load running of a cold engine can result in excessive white smoke and poor engine performance. No-load engine speeds should be kept under 1,200 rpm during the warm-up period, especially in cold ambient temperature conditions. If temperatures are below 32°F (0°C), operate the engine at moderate speeds for 5 minutes before full loads are applied. Engine Idling - In Cold Weather Avoid prolonged idling in ambient temperatures below 0°F. Long periods of idling may be harmful to your engine because combustion chamber temperatures can drop so low that the fuel may not burn completely. Incomplete combustion allows carbon and varnish to form on piston rings and injector nozzles. Also, the unburned fuel can enter the crankcase, diluting the oil and causing rapid wear to the engine. NOTE: An optional driver-controlled high idle speed is available on automatic transmission equipped vehicles with speed control. This feature allows the driver to select an elevated idle speed between 1100 and 1500 rpms. Your dealer can enable this feature. 5