Karin Haumann


Engine oil is the lifeblood of a truck’s engine, providing the protection and performance it needs. It also helps to reduce harmful emissions and increase fuel economy savings. In cold winter weather, drivers of diesel-powered trucks can use low viscosity oil to ensure their vehicles perform optimally in cold temperatures.

During winter, when temperatures drop significantly, a higher viscosity 15W-40 engine oil will flow at a slower rate when the engine is started, which affects the rapid lubrication of critical engine components. Low viscosity oils will flow to critical engine parts in cold temperatures more quickly, which provides strong engine protection. Drivers with diesel engines should switch to low-viscosity oil once the weather turns cold. Viscosity refers to how easily oil flows at a specified temperature.

One of the most versatile low-viscosity oils is 10W-30, which can often be used instead of 15W-40 because it is suitable for a wide range of diesel engine applications. The oil flows more readily at cold temperatures, ensuring faster lubrication and reducing wear on vital engine parts during cold starts. This improved flowability minimizes friction and wear on components like bearings and piston rings.

The benefits of using low viscosity engine oil extend beyond protecting engine components. When an engine starts quickly in cold weather, it places less strain on the battery and starter, which can help extend its lifespan and reduce the risk of costly breakdowns.

The advantages of low viscosity engine oils aren’t limited to cold weather operation. A low viscosity oil can enhance fuel economy throughout the year. This increased fuel efficiency can lead to cost savings over time, making them a practical choice for diesel engine owners.

In extremely frigid conditions, ultra-low viscosity engine oils like 0W-40 or 5W-40 are recommended. These oils provide exceptional cold-weather performance, ensuring the engine starts smoothly even in the harshest winter conditions.

In most cases, a 10W-30, 5W-40 or 0W-40 engine oil can be used instead of a 15W-40 engine oil. Before switching, check your owner’s manual or consult a vehicle service shop or dealer. These sources will help you select the right oil for your specific engine.

Low viscosity engine oils can operate in all types of weather and operating conditions while offering the engine protection and durability you need. They also provide superior engine cleanliness and fuel economy benefits.

Karin Haumann is an OEM Technical Services Manager with Shell Global Solutions. She provides technical and engineering support to original equipment manufacturer (OEM) customers. Her responsibilities include working with OEMs on new product development and testing of lubricants and new lubricant specifications. Karin is the chairperson for the American Petroleum Institute (API) New Category Development Team (NTDT) that is developing the PC-12 diesel engine oil category. The NCDT manages the development of new API Diesel Engine Oil Service Categories. For more information, visit https://www.shell.com/.