How does the cold affect your engine?

It may be only September, but winter is on its way. That said, there are some things you need to know about how to prepare your fleet, or even your own vehicle, for winter driving.

How does the cold affect your engine? 
While most 15W-40 viscosity grades will satisfy the cold-weather startup temperature requirements in the United States, engine oil specifications should be referenced to ensure that properties such as pour point, cold cranking viscosity and cold-temperature pumping viscosity meet an engine’s coldest operating temperature requirements.
Premium engine oils such as Mobil Delvac 1™ LE 5W-30 and 15W-40 are formulated to provide increased cold-weather startup protection at temperatures as low as -15 F°. Additional options that fleets or owner/operators should consider are using a semisynthetic like Mobil Delvac™ Elite,or full synthetic Mobil Delvac 1™ ESP, which is formulated to deliver exceptional protection even in severe cold weather conditions.
Engines will experience the highest wear during cold startup, as lubrication to bearings and the upper-engine hardware is limited during startup and initial warm-up. The engine oil’s viscosity at starting temperature is an important factor in determining whether or not an engine will start.
Using too heavy a viscosity during cold temperatures can result in inadequate lubrication during startup.
If the chosen lubricant has a viscosity that is too high, the oil filter bypass valve – assuming the truck has one – will open and allow unfiltered oil to bypass the oil filter (the bypass valve maintains the lubricating oil flow to the engine and prevents an oil filter collapse). The bypass valve will close as the engine oil warms up and thins out. It is equally important to adequately warm up an engine before loading it. The best practice is to idle for a short period and warm up the engine by operating at a low rpm and load condition.