Motorcycle engines are some of the most complex pieces of machinery ever invented. They are made up of hundreds (if not thousands) of metal parts, constantly grinding together to propel the vehicle forward.
Like automobiles, motorcycles come with care instructions you may find challenging to understand, which include lubrication.
The friction created within the motorcycle engines requires lubrication, making it an essential part of motorcycle maintenance. This means you must study how some things work so you can choose the right motorcycle lubricant for your bike’s engine.
In this article, you’ll learn the top three tips motorcycle owners need to decide which oil to select based on the type, viscosity, and grade of the product.
1. Understand the role of viscosity.
Viscosity describes a liquid’s resistance to flow. It is measured based on how fast a liquid runs when acted upon by external forces, such as gravity.
To help you understand this better, imagine water and honey. When poured into a container, the former flows down faster than the latter. This is because the molecules in the honey move against each other, creating more flow resistance compared to water.
In other words, the lower the viscosity, the faster a fluid moves through the engine.
Here are a few terms to guide you:
- Low viscosity oils are described as light and thin.
- High viscosity products are thick and heavy.
Now, you might be asking: What does oil viscosity have to do with the engine?
Viscosity determines the load-carrying capabilities of oil. It affects the product’s capacity to prevent friction between internal surfaces of engine components and improve the machine’s lifespan. It is also considered the most important physical property of a motorcycle lubricant.
Choosing the right oil based on viscosity also requires balancing regional temperatures and seasons, and the rider’s style of driving.
2. Learn to differentiate the types of motor oil.
Aside from viscosity, you must also study the characteristics of the various oils available. This will help you identify which ones to use on your motorcycle.
Read on to learn the difference between motorcycle oil and automobile lubricants and the different variants sold in the market today.
Motorcycle vs Car Oil
Unlike car engine oil, motorcycle lubricants come with a combined sump for the engine and transmission.
Car engine oil formulations also contain special friction modifiers that decrease wear and increase mileage for the automobile. If used on bikes, these modifiers may interfere with the clutch performance in a wet-sump application.
Though motor lubricants are very similar to automobile oils, they do not have the same level of friction modification. Plus, the motorcycle products are designed to flow better through narrower pathways in a motorcycle engine.
More importantly, manufacturers of mopeds, scooters, roadsters, and sports bikes have specific recommendations for the machines they make. Following the owner’s manual is imperative not only for maintaining your vehicle’s good performance but also for ensuring its warranty coverage.
Mineral oils (MO) are products or by-products of petroleum processing. They comprise the most basic type of engine oil and are mostly recommended for engines with smaller capacities. They are also perfect for bikes that do not get a lot of mechanical pressure during operations.
This type of motor oil is often recommended for new bike owners because mineral oil offers engine protection during the first few kilometres of the engine run-in. It is also useful for broader operating ranges, especially multigrade variants (more on this below).
However, mineral oils also have a few drawbacks. Their viscosity index improvers shears faster. Plus, MOs undergo more rapid degradation compared to synthetic oils.
Semi-synthetic (SS) oils are made from a combination of synthetic and mineral oils. They offer the best of both worlds: high-level protection offered by mineral oils and high-performance features from synthetic oils.
SS oils are best used for bikes with smaller capacities (or up to 250cc) with healthy horsepower. However, they offer better results for motorcycles that are not used for daily commutes or any other driving conditions that put the vehicle under a lot of stress.
Experts also recommend semi-synthetic oils for motorcycles that underwent mineral oil run-in.
Fully Synthetic Oils
Fully synthetic (FS) oils are deemed the best type of motor oil available. As the name suggests, they are manufactured artificially using pure polymers without impurities, making them the exact opposite of mineral oils.
FS motor oils are made with longevity and performance additives that help decrease wear. They also boost mileage and performance, thanks to their uniform molecules that reduce fluid friction.
Most importantly, they can maintain their quality level for a very long time than mineral or semi-synthetic oils.
Because of these features, fully synthetic oils are most recommended for high-performance motorcycles and racing machines.
3. Decode the SAE grading system.
Monograde lubricants are products represented by single designations (e.g., SAE-10 or SAE-40) and operate at a more limited temperature than multigrade oils.
It’s quite rare for monograde lubricants to be used for motorcycle applications because people drive these vehicles within a broader temperature range.
That said, motorcycles need a product that can provide equal levels of protection in both hot and cold conditions. This is where multigrade oil becomes handy.
Multigrade oils are much more suitable for year-round use. They are also designed to support longer oil change intervals and don’t cause as much battery drain as monograde oils.
Wondering how you can identify a multigrade motor oil? The answer lies in the alphanumeric code representing the product’s SAE viscosity grade.
Motor oils are categorised according to a grading system from the Society of Automotive Engineers (SAE) that uses a combination of letters and numbers.
To illustrate, consider an SAE 15w-40 grade motor oil.
The first few digits (15) indicate the oil’s viscosity at its current state. Higher numbers mean higher viscosity.
The “w” stands for “winter,” indicating that the following numbers indicate the oil’s viscosity at low temperatures.
If you see a number between 20 and 60 following the “w,” you should be reading it as the oil’s viscosity at higher temperatures (100 degrees Celsius). Since the digit indicated is “40,” it is safe to say that SAE-15w40 motor oil can be used in cold and hot temperature conditions.
But why is temperature so important? It all goes back to viscosity.
To illustrate the effect of temperature on viscosity, revisit the example mentioned earlier (i.e., honey). Depending on its current temperature, honey can either flow faster or slower.
When the liquid is cold, transferring it to another container takes time. When exposed to heat, the fluid runs quicker and more smoothly.
The viscosity needs to be at just the right level for optimal motorcycle lubrication. This will ensure that all parts are coated and protected well against friction without causing unnecessary wear to the engine.
Aim for Better Lubrication
Better motorcycle lubrication leads to improved performance and longevity. So, whether or not you use an oil change service when maintaining motorcycle lubrication, you need to understand the concepts behind these products to make the right decision.