The Royal Enfield Classic 350 has always made its place as a legendary motorcycle, blending classic styling and modern engineering. While its iconic thump and timeless design capture hearts, maintaining its engine performance requires careful attention, especially when it comes to engine oil.

Choosing the right engine oil is crucial for the longevity and performance of your Classic 350. This article delves into the intricacies of engine oil selection.

Engine Oil Grades for Classic 350

Engine oil viscosity, a measure of its flow resistance, is vital for engine lubrication and protection.

It’s denoted by a grade number, like “20W-40’“.

The “W” stands for winter, indicating the oil’s viscosity at low temperatures. The lower the number before the “W” means better oil flow in cold conditions, ensuring easier starting in colder climates.

The second number represents the oil’s viscosity at high temperatures. A higher number indicates thicker oil, offering better protection at higher operating temperatures.

The Royal Enfield Classic 350 owner’s manual recommends a 20W-50 grade oil with an API SL or JASO MA/MA2 specification.

These specifications ensure the oil meets the quality standards for your Classic 350. While 20W-50 is the official recommendation, 15W-50 is also a popular choice among riders. This grade strikes a balance between good low-temperature flow and high-temperature protection, suitable for most Indian riding conditions.

While most riders understand the basic concept of oil viscosity, some misconceptions exist about oil grades.

A common misconception is that higher viscosity oil is always better. While thicker oil protects better at high temperatures, it can also increase engine drag and reduce fuel efficiency.

Another misconception is that synthetic oil is always superior to mineral oil. While synthetic oil offers better performance and longevity, it may not be necessary for all Classic 350s, especially older models.

Royal Enfield Classic 350 Recommendations

Royal Enfield recommends a semi-synthetic 20W-50 oil for the Classic 350, a good starting point for most riders.

However, some 350 owners deviate from this recommendation based on their specific needs and preferences. They opt for fully synthetic oils for enhanced performance and longevity, while others prefer mineral oils for cost-effectiveness.

Few riders even prefer API SM-certified oil, which exceeds RE’s recommendation of API SL, for better performance.

Using non-manufacturer-recommended oil could cause engine damage or wear and may void the warranty, especially during the warranty period.

Synthetic vs. Mineral Oils

Synthetic oils outperform mineral oils in performance, heat resistance, and longer drain intervals compared to mineral oils. However, synthetic oils are generally more expensive. Mineral oils, while less refined, are suitable for older engines and offer good value for money.  

For the Classic 350, the choice between synthetic and mineral oil depends on riding conditions, engine age, and budget. Some owners report smoother engine operation and reduced vibrations with synthetic oils. Others find mineral oils adequate for their needs, especially for older models.

Climate and Riding Conditions

In hotter regions of India, where temperatures soar, a higher viscosity oil, like 20W-50, might be preferred for better heat protection.

Lower-viscosity oil, like 10W-40, could help with easy morning start-ups in colder regions.

Riding conditions also play a role. Frequent stop-and-go city riding generates more heat, potentially requiring a higher viscosity of oil. Sustained idling in city traffic can lead to faster oil deterioration in air-cooled engines like the Classic 350.

In hot climates, some riders have reported difficulties finding neutral and hard gear shifts with the recommended oil.

 Recommendations based on rider profiles:

  • New Classic 350 owners in moderate climates: Use the manufacturer-recommended semi-synthetic 20W-50 oil.
  • Riders in hot climates or with high-mileage Classic 350: Consider a 20W-50 fully synthetic oil for enhanced heat protection and engine longevity.
  • Riders in cold climates: A 10W-40 oil might help with easier starting.
  • Performance-oriented riders: Explore API SM-certified oils or high-performance synthetic options.

Conclusion

Understanding the factors that influence oil grade selection is essential. When deciding, consider your riding conditions, climate, engine age, and personal riding habits.