Light-duty vehicle drivers’ FAQs
Base oils, viscosity modifiers and performance additives are the three vital ingredients that go into engine oils. Careful selection and skilful blending goes into formulating each lubricant to provide maximum engine protection.
While most 15W-40 viscosity grades will satisfy the cold-weather start-up 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 are formulated to provide increased cold-weather start-up protection at temperatures as low as -26°C. Additional options that fleets or owner/operators should consider are using a fully synthetic like our Mobil Delvac™ XHP ESP, or our flagship Mobil Delvac 1 ESP series, which is formulated to deliver exceptional protection even in severe cold weather conditions.
Engines will experience the highest wear during cold start-up, as lubrication to bearings and the upper-engine hardware is limited during start-up 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 start-up.
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.
As temperatures drop, the same cold temperature viscosity phenomenon occurs with drivetrain lubricants as it does with engine oils. Following the engine warm- up procedures mentioned above will also allow for sufficient oil circulation to your drivetrain components. For general-service transmissions used in on- highway Class 8 vehicles where ambient temperatures of -26°C or below exist, a heat exchanger is recommended to make warm-up times faster. Fully synthetic SAE 50 transmission and SAE 75W-90 gear oil lubricants, such as Mobil Delvac 1 Synthetic Transmission Fluid 50, will provide better low-temperature fluidity than conventional oils, as well as help reduce wear, leading to longer equipment life and allowing for easier gear shifting while operating cold.
During winter weather conditions, vehicle suspension components can be subjected to more adverse conditions, such as increased water and contamination from road salting. Careful attention is needed to ensure that the suspension components are greased at a regular interval and the proper amount of grease is applied to help minimize the entry of road contaminants, and to replace grease that has been washed out due to excessive water exposure. It is also important not to over grease components as this can rupture seals and lead to reduced component life. A ruptured seal can lead to loss of grease and lack of lubrication as well as intrusion of road contaminants, water, dirt, etc.
Differentials and wheel hubs can be exposed to increased water intrusion during winter months from wet road conditions, high water at curbs, road flooding, etc. The lubricant condition should be inspected for water contamination when levels are checked. A visual inspection that shows a hazy or cloudy appearance or visible water droplets can indicate an excessively wet lubricant. Any indication of water intrusion should be investigated for the cause and the lubricant changed.