5W-30 Engine Oil Explained: What Do 5W-30 and SN/CI-4 Mean?
September 13, 2026
Choosing the right engine oil is important for maintaining engine performance, protection, and cleanliness. But with specifications such as 5W-30 and SN/CI-4 printed on oil containers, it can be difficult to know what they mean. Understanding these specifications can help you make a more informed choice for your vehicle.

5W-30 refers to the oil's viscosity, or how easily it flows at different temperatures. The “5W” describes its flow characteristics at lower temperatures, helping the oil circulate during cold starts, while “30” indicates how the oil performs at normal engine operating temperatures. This combination is designed to provide a balance between easy circulation during startup and dependable lubrication when the engine is hot.
The SN/CI-4 specification refers to API engine-oil performance categories. SN is associated with petrol/gasoline engines, while CI-4 is a diesel-engine service category. Together, these specifications indicate the types of engine applications and performance requirements the oil is designed to address. However, you should always check your vehicle manufacturer's recommendations before choosing an oil.
Elim 5W-30 Fully Synthetic Motor Engine Oil is formulated for petrol and light-duty diesel engines. Its fully synthetic formulation is designed to provide reliable lubrication, help reduce friction and wear, control deposits and sludge, and support engine cleanliness and efficient operation. It is particularly suitable for vehicles whose manufacturers recommend 5W-30 and compatible API specifications.
Using the correct engine oil can contribute to smoother operation, better protection of moving engine components, and long-term engine reliability. For the best results, always use the viscosity and specifications recommended in your vehicle's owner's manual and follow the manufacturer's oil-change intervals.
Elim 5W-30 Fully Synthetic Motor Engine Oil — advanced lubrication for reliable engine protection and performance.