Why is it so important to change your motorcycle’s engine oil regularly? And is there any real difference between car and motorcycle oil?

Our guide gives you the low-down.

What is the importance of motorcycle engine oil?

Engine oil is essential for keeping your motorcycle’s mechanical parts in good working order.

The motorcycle engine oil reduces friction and wear between the various components, thereby prolonging their life.

Engine oil also serves as a coolant and collects debris which is passed on to the oil filter. Acids and moisture are also neutralised by way of combustion. And last but not least, oil helps prevent oxidation – which is especially important if an engine stands unused for long periods.

Oil is so important that without it, there would be no combustion engine at all.

As a highly viscous liquid, oil is thick enough to create a barrier between metal components.

However, different oil types have different weights or grades and therefore different viscosities. With this in mind, certain oil grades only work properly within certain temperature ranges.

Years ago, different motorcycle engine oils were used at different times of the year; lighter oils in winter and heavier ones in summer. However, this was inconvenient and was not always effective.

Multi-grade oil

The advent of multi-grade oil presented an effective solution.

Multi-grade oil maintains viscosity across a wide temperature range. A school of thought asserts that multi-grade lubricants are not as effective as mono-grade oils, but this has consistently been debunked as a myth.

However, one drawback of multi-grade oil is that the additives which make it so effective do get degraded over time. For this reason, regular oil changes are required for your motorcycle, to maintain effectiveness.

Synthetic oils

Synthetic oils can outperform regular oils in some circumstances. Their molecular structure can be modified to suit a particular lubrication application.

There are basically two types of synthetic oil: Class IIIs, based on petrol oil stocks; and Class IVs, made in a lab.

While synthetic oils are highly effective – and constitute most motorcycle oils – there is a persisting idea that synthetics should not be used when breaking in a new engine. This was true when synthetics first appeared on the market, but it is much less true now. However, only the oil types recommended by the manufacturer of the motorcycle should be used.

Motorcycle-specific oils

A test carried out in 1994 concluded that motorcycle specific oils offered no tangible advantage over regular car engine oils. But over the last decades motorcycle specific oils have come into their own.

Crucially, motorcycle specific oils do not degrade as quickly as automotive oils. This is important in motorcycles, where the engine oil also lubricates the transmission.

Motorcycle oils also feature additional corrosion inhibitors – an important additive since motorcycles often sit for long periods with dirty oil inside them.

Conclusion

While there are various oils for specific situations, there really is no optimum oil for every possible riding scenario. It is best to follow your manufacturer's recommendations as regard which oil you use.

No matter what type of oil you use in your motorcycle, if you want to prolong the engine’s life, change its oil regularly.