If you’ve ever had to change your motorcycle’s oil, you’ve found that there are many different types. It is not always easy to know which motorcycle oil to choose, which is why we have put together this guide.
What is the role of motorcycle oil?
To understand the different motorcycle oils and their characteristics, let’s take a look at their roles. Note the plural used! Indeed, an oil is not only used to lubricate all the parts of the motorcycle. Of course, it allows the metal parts not to rub between them and therefore to wear less quickly. This even has the consequence of preserving the power of your machine. By creating a protective film between two parts to avoid friction, it can also seal it.
The engine oil is also used to cool the rooms, which heat by combustion or because of friction precisely. It is a less known characteristic of the oil, but quite important.
Finally, engine oil protects metal parts from corrosion and has a cleaning power.
Now let’s explain the criteria to look for to differentiate oils and know which one to choose:Mineral or synthetic oil?
An engine oil is composed of a main base, which is either mineral, synthetic, or semi-synthetic. The rest, between 5 and 30% depending on the oils, is a compound of chemical additives intended to perfect the characteristics of the oil, seen above.
A mineral oil is a conventional oil, obtained from the refining of crude oil. However, during refining, impurities can persist. This will be the role of additives for this type of oil. Mineral oil is becoming increasingly scarce, as modern vehicles use the engine. It will be suitable for some old cars, or for running a motorcycle.
Rather than transforming a product even if it retains contaminating elements, it is now customary to chemically manufacture the liquid hydrocarbons necessary for engine oil. This is synthetic oil. Better in all respects than mineral oils, they are the most used today. In particular, they remain more fluid and over a wider range of temperatures. They also degrade less quickly and are more resistant to stresses. They are highly recommended for hypersport owners.
The semi-synthetic oil, or Technosynthese, is a mixture of both; the mineral base undergoes a chemical modification to obtain a more robust product. It is the versatile product, corresponding to the majority of motorcycles and their use in all weathers.
How to read the viscosity of the oil?
You have seen on oil cans different ratings, from 5W30 to 15W40 through 10W40, the most common. What exactly do these figures mean? It is actually an SAE (Society of Automotive Engineers) standard.
More specifically, the letter w means that the oil resists very cold temperatures (W for Winter). The number before the letter W indicates the viscosity of the cold oil; the smaller the number, the more fluid the oil and suitable for cold starts in cold weather. The number following the letter W indicates the viscosity when hot, at 100 °C: the higher the number, the better the resistance of the oil to high temperatures and heavy loads.
Be aware that viscosity is directly related to the composition of the oil. Thus, the oils 5W30 and 5W40 are synthetic, the oil 10W40 is semisynthetic and the oils 15W40 and 20W50 are mineral.
2T engine oil vs. 4T
Pay attention to the 2T (for 2 stroke) or 4T criterion indicated on the oil container. Depending on how your engine works, oil will have a different role. On 2-stroke engines, the oil ends up being burnt with the fuel. On 4-stroke engines, the oil remains in a crankcase-parts circuit; it must therefore not degrade quickly.
API, ISO, JASO, ACEA standards
It is a criterion determined by committees or associations: American for API, Japanese for JASO. The resulting standards are more or less in the same form: the higher the letter, the more efficient the oil and meets the most recent criteria. To give you examples, the current standards are as follows:
- API TC and JASO FD for 27,
- API SM and JASO MA2 for 4T.
How much does a motorcycle oil cost?
The prices differ according to the brands and specificities of the oils, but count between 10 € and 20 € per liter. Do not fall into the trap of preferring a car oil to put in your motorcycle. Car oils do contain car-specific additives that would be harmful to your clutch.
Conclusion: which oil to choose according to the bike?
You have all the keys in hand to make your choice. We can not add to follow the recommendations of the manufacturer, which are the minimum to follow. Here are our latest practical tips to adapt it to your use:
- Most of the time your bike stays below 8-9000 rpm; you take it out in all weathers, you live in a temperate zone and you need it to start up and perform quickly in the morning. Choose a semi-synthetic oil in 10w40
- You compete or at least your motorcycle is constantly above 9-10000 rpm: synthetic oils type 5W30 or 5W40 will be ideal. This also applies to city dwellers who use their engine a lot, including scooters!
- You are running in, or you live in a hot region all year round: oils in 15W40 (or 20W50 for old engines) will be sufficient. Please note, however, these are mineral and not synthetic oils.