Engine oil: What every car owner MUST know

Engine oil is something you will only hear about when you go to get your car serviced or when something goes wrong and oil pressure lamp comes on in the instrument cluster. So what exactly is engine oil and what does it do? We tell you everything about it.


Let’s begin with the what. The engine oil is poured into the oil sump located in the engine. As the parts rotate, the oil gets thrown around lubricating all the parts of the engine. The main job of engine oil is to provide lubrication so that there is no metal to metal contact. Its also acts as a heat extractor, keeping the parts cool. Another thing the engine oil does is act as a cleaner and removes dirt(if any) from the engine components. These then settle down at the bottom of the sump.

How do they vary? All engine oils have a numerical rating which is what differentiates one from an other. There are two types of oils, single grade and multi grade. Single grade oils are those that are represented by a number and then W (5W, 10W, etc) where as the multi grade oils are represented by a number on both sides of the W (10W30, etc). ‘W’ stands for winter and the number before depicts the cold viscosity rating. The lower the number, the lower the temperature it will work in. The number after the W will tell you the thickness of the oil at higher temperatures. These grades are mentioned in your car’s owners manual. Ensure that you stick to them.

Types. There are three types of engine oils, synthetic, mineral and semi-synthetic. Mineral oils have been dug up from the earth and undergo a refinement process. These are cheaper to buy but may have some impurities which would mayn’t provide very smooth lubrication. Synthetic oils are derived from mineral oils and have certain added chemicals that provide for smoother lubrication. Semi-synthetic are a mix between the two.


Additives. Some oil companies have added metal (titanium) to the engine oil which help to improve the lubrication process. Others have introduced magnetic particles in their oils to help reduce wear and tear during start up. Most of the engine wear occurs during start up. Magnetic particles get stuck to the engine while shutting the car thus improving the lubrication while starting the car later.

castrol magnetic

Switching oils. If you do plan to change from mineral oils to synthetic oil, ensure you get the oil drained completely and get the oil filter changed before switching. Also, ensure that the synthetic oil is compatible with the engine requirements before doing the transition.


Expiry. Yes, as surprising as it may sound, engine oils do have an expiry date. There is a reason why manufacturers suggest that you change your engine oil in particular intervals of time (kms/age). The properties of the oil deteriorate over time and hence there is a time interval suggested as well. This means that even if you don’t drive the car the whole year, you will still have to get the engine oil changed.

How to check. Every engine has a dipstick which is to be pulled out to check the engine oil. This is to be done on a cold engine to ensure that the reading is correct. The dipstick has markings on it that show the minimum and maximum level. Pull the dipstick out, clean it and insert it back in. Pull it back out and see the level of oil. If you have been driving your car through excessive traffic for a long time, we would recommend you check your engine oil level once a month atleast.


Low oil pressure lamp. If the oil pressure lamp comes on, check the amount of engine oil present in your car. If you are running very low, top-up before continuing. Driving with low engine oil may result in your engine getting seized. That could be an expensive affair.

If your engine is consuming a lot of engine oil, get it checked. There could be a leak or some issue which is causing the oil level to reduce.