What is the difference between Castrol Edge FE and SN?

[VanMartin]

Here are the differences between Castrol Edge FE and SN: 1. Different properties: The FE oil contains the latest titanium fluid technology and does not fall under the category of oil grades, such as SN, which refers to the oil grade. 2. Different grades: The 'S' in SN stands for gasoline engine lubricating oil, and 'N' represents the grade, arranged in the sequence of the 26 English letters. Currently, the highest grade is N, while 5w-30FE has no grade. 3. Different viscosities: The number before 'W' represents the flow viscosity at low temperatures. The smaller this number, the better the low-temperature fluidity of the oil, providing better protection for the engine during cold starts. The number after 'W' indicates the viscosity of the oil at 100°C. The higher the number, the higher the viscosity, offering better protection for the engine at high temperatures.

[LeEmmett]

I often do maintenance for older cars, and the main differences between Castrol Edge FE and SN can be seen in two aspects. FE refers to a fuel-economy formula, generally with lower viscosity, such as 0W-20/30, which is particularly friendly to new cars, offering fuel efficiency and smooth operation. SN represents the older API standard, with more basic oil and additive technology, suitable for engines that aren't picky. Nowadays, the mainstream is the SP standard, and after upgrading, Edge offers better cleaning performance, can withstand low-speed pre-ignition, and provides particularly noticeable protection for turbochargers. Personally, I recommend prioritizing those with SP certification. If you really can't find one, then use SN. For older cars, be careful not to use FE variants with too low viscosity, as they might cause oil burning.

[Velazquez]

From a technical perspective, the core difference between Castrol EDGE FE and SN lies in their standard positioning. FE focuses on fuel economy, with formulations like 5W-30 FE reducing power loss by lowering high and low-temperature viscosity, achieving approximately 3% fuel savings in actual tests. SN belongs to the older API specification, relying primarily on zinc-phosphorus anti-wear formulations, offering inferior protection for modern engines compared to the current SP standard—the latter utilizes calcium-magnesium additives for more effective deposit control. Notably, some SN products remain on the market; it's advisable to check packaging for SP/GF-6A dual certification. Turbocharged vehicles in particular should avoid SN to prevent low-speed pre-ignition risks.

[VanAniyah]

Simply put, it's the difference between old and new products. Nowadays, when you buy Edge, seeing FE means it's the energy-saving type. Pouring in the watery-thin 0W-20 makes the throttle response exceptionally crisp. SN is already outdated, as everything has now been upgraded to SP, offering much stronger protection for sealing rings. Just the other day, while helping a friend pick out engine oil, I stopped him from buying the old SN stock the repair shop was clearing out—his new Mondeo with a turbo from last year could risk engine damage with SN. Always choose the one with the SP label, and for extra assurance, look for the small GF-6A text at the bottom right of the packaging.