Engines have metal parts that move to generate the power that propels a motorcycle forward. A motorcycle engine oil lubricates these parts to ensure they do not overheat or wear out prematurely.
The oil pump circulates the motorcycle lubricant inside the engine once the motorcycle is on. The oil then fully coats the metal parts, while the steady movement of the parts also continuously draws in the oil between them.
The engine oil provides a liquid barrier between these moving metal parts. The oil fully separates the parts, facilitating their smooth movement and minimising friction between them.
That being said, which engine oil is for you? There are hundreds of motorcycle engine oils in the market, so choosing one can be difficult.
When in doubt, follow your motorcycle manufacturer’s recommendations. You can find it in your owner’s manual. However, for general guidance, here’s crucial information about the three main types of motorcycle engine oils.
- Mineral Oils
Mineral oils are engine oils derived directly from crude oil. An oil processing facility performs fractional distillation to break petroleum into distinct fractions or groups of similarly sized molecules. One of these fractions is packaged and sold as lubricants for motorcycle engines.
The Advantage of Using Mineral Oils
Mineral oils are affordable. They also provide adequate lubrication, particularly for newer (i.e., cleaner) and smaller capacity (125cc and below) engines that do not generate high mechanical outputs.
The Disadvantage of Using Mineral Oils
Mineral oils undergo fractional distillation and additional refining to eliminate unwanted hydrocarbons and impurities. However, these processes cannot remove all contaminants. Over time, the remaining impurities can accumulate and cause build-up, leading to engine inefficiency.
Likewise, mineral oils are typically thicker than synthetic oils. As such, they don’t flow as readily, so some parts could remain unlubricated or unprotected for a time as the engine oil circulates.
Mineral engine oil molecules also don’t bond as well in higher temperatures. This reduced viscosity in high temperatures can mean diminished protection for vital engine parts.
Finally, mineral oils break down or degrade much more readily than synthetic oils. This means you’ll need more frequent engine oil changes.
- Semi-Synthetic Oils
Semi-synthetic oils are oil blends. Typically, there is 70% mineral oil to 30% synthetic oil in a semi-synthetic oil product, but this ratio can vary.
Semi-synthetic oils also usually contain performance-enhancing synthetic additives. Additives can improve an engine oil’s anti-corrosion properties, lubricity, detergency, high-temperature resistance, and cold-engine start protection.
Semi-synthetic oils are usually prescribed for mid-capacity (125cc to 180cc) engines.
The Advantage of Using Semi-Synthetic Oils
Semi-synthetic oils perform better than mineral oils. They should provide adequate protection even in short bursts of performance riding. Furthermore, they are relatively affordable.
The Disadvantage of Using Semi-Synthetic Oils
They are more expensive than mineral oils. And while they offer better engine protection than mineral oils, they do not provide as much protection as synthetic oils.
- Synthetic Oils
Synthetic oils are laboratory-synthesised engine oils with uniformly sized molecules and are devoid of the natural contaminants and impurities often found in mineral oils. They are typically prescribed for high-output engines (200cc and higher).
Synthetic oils have stable viscosity; i.e., their thickness does not vary significantly across a wide range of temperatures, ensuring superior protection even in highly fluctuating temperatures and conditions. They have lower sulphated ash, phosphorus and sulphur content — meaning fewer emissions. Finally, they can significantly improve engine efficiency, thereby boosting fuel economy.
Synthetic oil manufacturers also enhance (or add to) the positive characteristics of synthetic oils by using additives. These enhance the following qualities of synthetic oils:
- corrosion-resistance
- lubricity
- detergency
- high-temperature stability
- low-temperature flow
- degradation resistance
Caveat: Some engine oil brands may sell some highly refined and thoroughly processed mineral oils as synthetic oils in certain markets.
The Advantage of Using Synthetic Oils
Synthetic oils provide consistent, superior lubrication even in extreme conditions, fewer emissions and better fuel economy. This is the best lubricant for high-performance riding.
Synthetic engine oils also often contain anti-wear additives that coat metal parts that temporarily protect them from undue wear and friction.
Such anti-wear additives are helpful when the engine has insufficient lubrication. This is the case after you turn on your motorcycle; the oil pump will circulate the oil inside the engine. This is also the case in heavy-traffic conditions when oil pressure is low because of the low engine speed.
Synthetic oils are also more resistant to breakdown. This means longer engine oil change intervals.
The Disadvantage of Using Synthetic Oils
Synthetic oils are significantly more expensive than mineral oils and semi-synthetic oils as they must be synthesised in a lab (or undergo exhaustive refining and processing as in the case of synthetics derived from mineral oils).
The Best Motorcycle Engine Oil
The best motorcycle engine oil is what your motorcycle manufacturer prescribes for your engine.
Generally speaking, however, synthetic lubricants are the best among the three types of motorcycle engine oils, providing the best lubrication protection even in extreme conditions. Synthetic is definitely best for Yas Marina circuit driving, for example.
Besides providing enhanced protection for demanding rides, synthetic engine oils also offer other benefits. They are more resistant to breakdown, keep your engine cleaner and lead to fewer deposits. They can also help your engine reduce emissions and achieve better fuel economy.
Thus, if you want superior protection and many other benefits, use a synthetic engine oil that satisfies the requirements of your motorcycle manufacturer.