Why is SL engine oil more expensive than SN?
2 Answers
In terms of grade, SN is two levels higher than SL. Below is the relevant introduction: SL/SL and CF/CG: SL/SL: indicates use for gasoline engine vehicles, CF/CG: indicates use for diesel engine vehicles. The specific classification of automotive engine oil: 4 types for summer use, 6 types for winter use, and 16 types for all-season use. The summer oil grades are: 20, 30, 40, 50. The larger the number, the higher the viscosity and the higher the maximum applicable temperature. The winter oil grades are: 0W, 5W, 10W, 15W, 20W, 25W. The symbol W stands for Winter, and the smaller the number before W, the lower the low-temperature viscosity, the better the low-temperature fluidity, and the lower the minimum applicable temperature. Then there are all-season oils, with grades: 5W-20, 5W-30, 5W-40, 5W-50, 10W-20, 10W-30, 10W-40, 10W-50, 15W-20, 15W-30, 15W-40, 15W-50, 20W-20, 20W-30, 20W-40, 20W-50. The smaller the number representing the winter part, and the larger the number representing the summer part, the higher the viscosity and the wider the applicable temperature range.
It's actually quite rare for SL-grade oil to be more expensive than SN-grade, but if you encounter this, it's likely due to market supply and demand. I drive an older car and have always used SL-grade oil. With more and more new cars on the road, many oil manufacturers have shifted their focus to SN-grade, reducing SL production. As a result, SL has become rarer. Just like antiques, scarcity drives up value – maintaining those older engines now costs more. SN oil is the newer standard with more eco-friendly formulations and higher R&D costs, typically commanding a premium. But with SL still in decent demand, when supply tightens, prices rise. When choosing oil, don't just look at price – check the API certification and your vehicle manual requirements. Using the wrong oil can lead to premature engine failure and higher repair costs. Overall, switching to the newer SN specification is more cost-effective and provides better long-term engine protection.
