Why engine oil need to be replaced?

Why engine oil need to be replaced?

Why engine oil need to be replaced?


We at one or another time have read or heard it that one should change the engine oil of the vehicle to keep the vehicle’s engine in perfect condition. Changing the engine oil for every 3000 miles or 5000 miles or at any fixed intervals is not necessary nowadays. Changing the engine oil is not a rocket science. One must have done that at one point of their life or another. But the important question is what should be the time interval of changing the oil? So, here is an article on why and when one should change the oil of the vehicle.

Heat breaks down the oil which makes it gluey or watery (sometimes both) and as a result it doesn’t lubricate properly. So, more it remains in the vehicle, the more it gets dirtier. That’s why it is necessary to change the oil after a certain period of time. By changing the oil regularly after a specific interval on the manufacturer’s recommendation, one can keep the engine safe. To reduce repairs and improve a vehicle’s performance, it is important for the owner to follow the oil change recommendations given in the manual.


Another question that arises here is why there is a need to change the oil after a regular time period. Why can’t we change the oil for one time and it works for the entire lifespan of the vehicle. Oil uses complex additives and detergents to prevent deterioration and development of sludge. To be precise, in vehicles additive wears out more than the oil. Eventually all motor oil wears up after a time period, irrespective of the oil one uses (conventional, synthetic or synthetic blend) and need to be changed regularly. Another factor that decides when to change the vehicle’s oil is one’s driving habits. How one drives the vehicle or use it, affects the maintenance intervals seriously.


Extreme conditions such as if one drives a lot in city or heavy traffic, goes on short trips frequently and park the car for long so that the engine cool down. Some other extreme conditions such as driving regularly in hot weather or in regions with a lot of dust, diesel or turbocharged engine, or tug heavy loads all the time. In any of these conditions, change the oil with every 1,000 to 3,000 miles on older vehicles. While for new vehicles, manufacturer’s recommendation is required for extreme use.


Along with oil change at regular interval, other recommendations that one should follow are:-

  • Inspection of brake system every year or 15,000 miles, whichever is first.
  • Annual change of the air filter or when visibly restricted.
  • Tire rotation on manufacturer’s recommendation or every 6 months or 5,000 miles.
  • Monthly check of tire inflation pressure.


Customers generally follow the old mile myths just because they are not aware of the advances in the automobile industry. Earlier, it was standard to change the vehicle’s oil at every 3 months or 3,000 miles, but the introduction of synthetic oil and other refinement of oils have lengthened the intervals to change oil. The longest oil change interval is for Jaguar’s vehicles of 15,000 miles, while the shortest one is of 5,000 miles in some Hyundai and Kia models with turbo engines and Toyota models that use non-systematic oil. Some automakers such as Ford, Volkswagen, Porsche recommend changing the oil on every 10,000 miles. In BMWs with synthetic oil one can even drive up to 15,000 miles without changing it.


Now, most of you might be thinking that how come the time interval to change the oil has increased. So, some reasons are-

  • Nowadays, oils have more strength which protects the engine from wear and heat and offers good fuel economy with low emission.
  • Today’s engines have high tolerance.
  • These days, vehicles have oil life monitoring system that notifies the driver when to change the vehicle oil.


Some signs that can help when to change the oil are:-

  • when the check engine light on the dashboard won’t go away.
  • when the engine making loud noises than usual.
  • when the oil looks dirty and black.
  • when the oil level drops.



To sum it up, one should consider changing the vehicle’s oil more often, if one tends to drive frequently at high speeds, have an older engine or live in an area that is particularly hot, cold or dusty. Don’t just get carried away with myths, think logically. And still you have any doubt about when to change the oil, you can change it after every six months, when you will be rotating your vehicle tires.


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