Engine oil is like blood circulating through vehicle’s body. It is essential to maintain good health of car. Laxity in changing the engine oil at right time is not only harmful to you car’s engine but also your pocket.
Engine oil commonly called motor oil performs many function like lubrication, cooling, cleaning, protection and sealing. Engine has many moving parts. It cause friction and leads to wear and tear. Oil reduces friction between moving parts in the engine, which helps prevent wear and tear.
It release heat from the engine by aiding the coolant. It also clean engine clean by suspending microscopic deposits of dust and combustion residue in the oil. These impurities are then carried to the oil filter, where they are trapped. It protects engine parts from corrosion and oxidation. It can fill in uneven surfaces
Does you car needs change of engine oil?
There are two scenario to know if its time to change your engine oil. First, you exactly know (miles/kilometers) when was your car’s oil was changed last time. Second, you are completely unaware of time when it was changed previously. Let us see both of them.
1. Changing Engine oil based on Miles/ Kilometres
Right now synthetic engine oil are most popular. The time interval for oil change is 7500 to 10000 miles or 10000 to 15000 kilometers.
| Type of Engine oil | Distance Interval | |
| Miles | Kilometers | |
| Conventional Oil | 3000 – 5000 | 5000 – 8000 |
| Synthetic oil | 7500 – 10000 | 10000 – 15000 |
From point of view of duration interval – conventional oil should be ideally changed every 6 months and synthetic oils should be changed every 12 months. Besides, driving condition like traffic, dusty roads, or extreme temperatures also affect the quality of oil. How to check oil quality is covered in second part below.
2. Changing Engine oil based on criteria like Volume, Colour and Viscosity
When you buy a new car or you have failed to register the kilometers of oil change, it becomes difficult to know time of changing oil. During such situation, you can arrive at conclusion whether you should change it or not based on volume, Colour and viscosity of oil.
I. Volume
The volume of engine oil can be checked by by evaluating the dipstick given beside car engine. Pull it out and wipe off all the oil with a cloth or rag. As shown in image it should not fall below minimum level and it should not go above maximum level.
II. Colour
The colour of brand new oil is clear yellowish/golden. With it becomes darker. It becomes dark brown and than black. For diesel engine, the colour of oil changes to black as soon as you turn on the engine. It’s completely normal.
For gasoline/petrol car, the colour change is gradual with use. Black colour usually mean that it is time to change the oil. But it should be evaluated along with viscosity.
Oil can also become turbid like soil in water. That is the most alarming situation. It occur when coolant become mixed with engine oil. If you see such colour take your vehicle to car mechanic immediately
III. Viscosity
New oil is free flowing. It is thin and spreads easily between fingers. It gradually becomes thicker/viscous with use. Black colour along with thick viscous oil mean that you should change the oil without further delay.
Personal Experience
I once draw my gasoline/petrol car up to 15000 miles or 20000 kilometers. I had regularly checked the status of oil. It appeared fine. When mechanic drained oil out it was very viscous. He asked me to not make such delay again.