There are many opinions on what oil is best and how it affects your engine.
One of the most common discussions touches brand, grade and perhaps price. But what are the basics about oil?
Oil primarily has one function – easing movement of different parts – however, beyond this there are other functions such as:
Prevents friction and wear
Well, did you know that some of the moving parts within your engine never really touch? They ride on a thin layer of oil.
Oil keeps moving parts separated from each other thus preventing damage that might result from friction and wear.
Beyond preventing friction, oil also acts as a cooling agent that carries away heat generated from combustion.
According to Ivan Kyeyune, a mechanic on Rubuga Road, low engine oil level cause the engine temperature to rise, therefore.
“Low oil levels are dangerous to the engine. It can cause a lockup or even fire resulting from the continued parts knock-on effect,” he says.
Cleaning inner parts of the car
Engine oil will constantly trap dirt from moving into the delicate parts of the car.
It holds up non-engine lubricates, picks up dirt and contaminants as well as combustion by-products.
According to William Kato, a Land Rover specialised mechanic in Nsambya, Kampala, oil acts as a sponge with the ability to pick up and hold fluids and dirt, among other things.
“When a sponge becomes over saturated, it can no longer hold any more fluid,” he says, emphasising the need to check and change oil more often.
Oil, he says, gets contaminated and will fail to hold intruding elements that may get deposited in engine, causing sludge, a process that might lead to engine lock-down.
“Regular oil change will remove suspended contaminants before sludge can form, helping keep the engine running cleaner, smoother and more efficiently,” he says.
Rating engine oil
Engine oil is rated with two labels such as 10W-30 or 5W-40 to describe the behaviour of the oil in cold and hot conditions.
For instance, according to Kato the left number in 10W-30 describes how oil will behave in colder conditions, while the right number describes the behaviour in hot conditions. The W conveniently stands for “winter” and the lower the number, the better the performance oil.
The second number (30) relates to how well the oil flows at higher temperatures and the more the number the thinner the oil gets, the better the performance.
However, when oil gets too thin, especially among used cars, it might fail to separate some parts from each other which might instead cause damage.
Therefore, according to Kyeyune, you must always maintain a delicate balance as “oil needs to flow well when the engine is cold but also maintain a film at higher temperatures to keep metal parts lubricated and separated”.
Synthetic oil is the best option for any car; however, it comes at a price.
It has the capacity to offer better low and high temperature flow and sieves out much of the external deposits.
It is highly recommended in high-performance applications, especially where the engine has a tight tolerances, high temperature and high compression such as supercharged and turbocharged engines.