The moto-diary: How to pick the right engine oil for your vehicle

Did it ever happen to you that you were presented with multiple options upon seeking advice on which engine oil to use for your vehicle?

Even when a group of people use the same vehicles, their engine oil preference is not often the same. Their biases might have spurred from years of brand loyalty or user experience however, it does not answer your question - "which engine oil is best for my bike or car?"

This week, we will provide you a basic idea on the differences between engine oils. This guide could help you choose the right engine oil for your ride.   

Let us start with the most important attribute of a lubricant (engine oil). Understanding viscosity promotes the ability to reduce engine wear, enhance fuel economy, and generate more horsepower, period. 

Viscosity is the measurement of a fluid's resistance to flow. It describes the internal friction of a moving fluid. A fluid with high viscosity is thick; it resists motion because its molecular makeup gives it a lot of internal friction. A fluid with less viscosity is thin and flows better than high viscosity fluid. 

In order to choose the right engine oil for your motorbike, you must understand the grade of an engine oil's viscosity as well. You will find the viscosity grade highlighted on all sorts of engine oil packaging such as "10W30" and "10W40".

The letter that separates the viscosity grade - "W" refers to "winter" and is the key to understanding viscosity grades. 

A 10W30 grade engine oil is a multi-grade lubricant that consists of  two viscosities. Around forty years ago, there were different grades for cold and warm weather. A "10W" was once a typical winter grade and now, better synthesis like "5W" or "0W" have been adapted by lubricant manufacturers. 

A 5W or a 10W flows well in cold weather and protects the engine during ignition however, it is too thin to use during summer. A 30/40 grade oil, on the other hand, is thick enough to protect the engine at warmer temperature. 

A multi grade engine oil - 10W30 carries the winter cold start flow properties of a 10W and the summer, high temperature thickness of a 30 grade as well. 

Multi-grade oils can stay as close to the optimum viscosity over a range of temperatures - not too thick when it is cold and not too thin when it is hot.

The difference between two multi-viscosity grades - 0W30 and 10W30, is indicated by how well each flows at minimum level. 

The viscosity of hot oil is measured using different test parameters than that of cold oil. Thus, the numbers after the "W" do not relate to the numbers in front of the "W". The difference between 10W30 and 10W40 grade is the high temperature viscosity; the latter is thicker than the former at high temperature.

If armed with knowledge of viscosity grades, how can we put it to good use? 

Remember that using a high viscosity engine oil can result in excessive oil temperature and drag. Using an oil with a low viscosity can lead to excessive metal to metal contact between moving parts in an engine. Using the correct viscosity makes igniting engines more convenient; reduces friction and also slows engine wear.

If you want to protect the engine more while ignition, use a synthetic 10W40 instead of a conventional 20W50. 

The synthetic 10W40 flows easily while maintaining enough viscosity to protect piston skirts, bearings, and chamber walls when it gets hot. The improved temperature stability of synthetic engine oils make them a better choice for high performance engines. 

However, the viscosity of synthetic engine oil changes with temperature as well. 

In order to select the correct viscosity, you must know the engine oil's operating temperature. Engines that run on high operating oil temperatures require higher viscosity oil.

Here is another thought regarding viscosity. 

It is vitally important to keep internal engine clearances in mind. Looser clearances in the engine and oil pump require higher viscosity oil to maintain oil pressure. Tighter clearances need lower viscosity oil, which provides better cooling and improved horsepower.

Now, among the current engine oils being sold in the market, we have a lot of options for both two and four wheelers but many users often choose the wrong engine oil for their vehicles which eventually leads to the engine's early demise. 

The availability of a wide range of varieties of engine oils like Motul, Sheel, and Castrol has also brought about fake and falsely graded engine oil packages being sold in the market. Thus, we recommend buying engine oil straight from importers and distributors if you want a stress-free maintenance scheme for your vehicle. 

Generally mineral oils such as 20w40, 20w50, or 10w30 used in two wheelers tend to stay optimum in the first 500-600KM of use in our regional temperature. The semi-synthetic does justice till the 750-900KM, and the full synthetics tend to stay actively optimum till 1200-1400KM of use. 

Keeping up with the right viscosity and drain intervals of an engine's oil surely keeps your vehicle more durable. Components like air filter and spark plug, if changed on time, can also result in the optimum performance to be peeked and felt with more frequently.  

So, since fluid, air and motion is what hearts of machines are all about, it should always be your first priority to keep it healthy. 

Sahil Ahsan is an Operation Specialist of the automotive channel - Throttle Alpha.