Are There Benefits to Warming Up the Engine on a Cold Morning?
Metal-to-metal contact is when all machinery components wear. The application of lubricants to a mechanical environment is what diminishes that wear. When your vehicle has been sitting for any appreciable time like overnight, the oil has settled into the bottom of the oil pan of the engine and into the lower areas of all the other components containing fluids. When the vehicle starter is activated and the engine begins to turn over the oil pump comes to life before the engine can fire. Oil is quickly pumped forcefully throughout the engine and then the engine starts. With lubricants already in the upper areas of the engine from which they drained during the shutdown, there is minimal metal-to-metal contact.
Even in warmer climates or summer weather the oil must reach operating temperature before it works most effectively. The colder the ambient temperature, the longer it takes for the oil to be warm enough to do the job. A vehicle owner who wants to prolong the life of the mechanical components of their car, truck or conversion van should plan on allowing the engine to warm up at an idle for at least a minute in warm weather and up to four minutes when the temperature is hovering around freezing. At near freezing temperatures it may take as much as three minutes or more before the oil is warm enough to circulate freely in an engine.
When the vehicle is first started after a long, cold night, the driver should avoid revving the engine until the temperature gauge begins to rise. This ensures that the metal parts are protected from frictional wear. This practice may add thousands of miles to the mechanical life of the engine. To warm up the transmission and differential fluids the vehicle should be driven slowly for the first few miles. If the vehicle has been parked for only a few hours and had been adequately warmed up when first started, it isn’t necessary to be so protective.
Another consideration is to select the proper lubricants for the season. Modern multiple viscosity motor oils are the best because they will perform like low viscosity oil when cold and then act like a much more viscous oil when they are hot. This is accomplished by the addition of polymer viscosity enhancers that expand when warm, thus making the oil thicker and more protective of the warm engine parts.