The modern internal-combustion engine is one of the most complicated machines we use with a plethora of parts that move at high speeds during operation. Even a minuscule amount of friction can cause monumental amounts of wear and tear which can reduce the life of the engine and consequently of the car by a huge degree. One very important part of the car engine that mitigates this wear and tear is the engine oil but it does not last forever. The engine oil has to be changed at regular intervals so that the engine is well lubricated at all times and the car is able to function in the most optimal manner for a long time.
The issue arises with deciding the right time after which the oil should be changed. Most car manuals will specify a certain time period or a certain number of miles after which the engine oil should be changed. The thing that we need to realize is that this number like many of the other specifications of a car is a ballpark figure that is supposed to be a good guideline or a starting point. This number is reached by making certain assumptions about the running of the car and as such can produce varying results for different people. To get the best results, you will have to delve a little deeper into the whole function of the motor oil and the various factors that decide its optimal life. That will allow you to take the best call with regards to frequency of oil change.
Why engines need oil?
A typical car engine has a lot of moving parts. That is a lot of potential for wear and tear. All this has to be lubricated properly to keep everything running smoothly without grinding into each other. You cannot use just about any oil for this lubrication purpose. It has to be able to withstand high temperatures as well as huge fluctuations in temperatures. Over time, it will get contaminated and that will further reduce its efficiency. What is more, the motor oil has to work equally well when the engine is cold like when it has been just turned on, or very hot like when it has been running for a few hours. As we alluded to before, the oil will degrade over time and the rate at which this degradation will take place will depend on factors like how much the temperature fluctuates, how dirty the environment is, the constituents of the oil, and so on. It is not as simple as looking at the odometer. Let us take a closer look at the various intricacies associated with oil-change.
Understanding what normal driving is:
Any user manual is all about the fine print and your car’s user manual is no different. If you look at the magic figure that tells you when to change the engine oil, you will find an asterisk next to it that leads to a fine print that says “under normal driving conditions” or something to that effect. This is where all the inconsistency comes in as different manufacturers might have different definitions for normal driving conditions. Try to find what exactly they mean by this statement and that can help you decide the exact frequency for an oil change. If your car is driven in a more strenuous condition compared to what the manufacturer describes as normal, then you would need to change the oil more frequently. If your driving loads are lighter then you can go beyond the number advised by the manufacturer. Usually, highway driving is easy on the car and so is dry and mild weather. The motor oil can last longer under such conditions and you can stretch the duration to about 7,000 miles between oil changes. If on the other hand, you tend to drive in hot and humid conditions on crowded city roads then the oil change has to be more frequent and in the 3,000-mile range.
The type of oil:
Standard motor oil is organic in nature to some extent and breaks down faster. It also takes time to warm up and reach its optimal operating temperature. The upside is that it is cheaper and can be replaced more often. Synthetic motor oil, on the other hand, is more durable and has a wider operating temperature. The downside is that it can cost to twice or thrice as compared to an organic option. The obvious big question is which one to choose and that depends on two major factors – the environment and your lifestyle. If you live in a place that has stable weather conditions then the cheaper organic motor oils are good enough. If on the other hand, there are huge fluctuations in temperature throughout the day then a synthetic oil is your best bet. The lifestyle part is very simple. If you mostly drive in a smooth manner without exerting the car too much then a regular motor oil is good enough. If, however, you have to drive through a lot of stop-go traffic, or if you use your car for towing purposes then you are better off with a synthetic engine oil. In short, synthetic engine oil is more resilient, will last longer, and can take a wide range of fluctuations in the environmental conditions while regular organic engine oil is best for a car that is used in an easy-going manner.
The state of your car’s engine:
This too plays a big role in the life of the engine oil. The engine casing should ideally not have dust and sludge buildup but as an engine gets older and more worn out, its propensity to get a buildup of all these unwanted elements increases. This will reduce the ease with which the oil can flow and its ability to properly lubricate every nook and corner in the engine. The popular misconception is that older cars require more frequent oil changes. Brand new cars that haven’t been broken in actually need quick oil changes, sometimes as frequently as 1,500 miles but as the engine is broken in and begins to ride smoothly, the oil will need replacing less frequently. Beyond this point, it all comes down to maintenance. If the engine has been maintained well and its smoothness has been retained then you call follow the same regiment as before but if the engine has begun to lose its smoothness and has begun to produce more noise and smoke then that means that the engine is well beyond its prime and will need frequent oil changes.
The type of engine:
Not every engine is made equal and some are kinder on the oil than other. The general rule of thumbs is that the more complicated and performance-oriented the engine is, the more frequently the oil will need a change. This is because such an engine will work the oil harder by putting it through greater temperature fluctuations as well as mechanical stresses. An engine with turbochargers and superchargers will cause massive fluctuations in the operating conditions and the motor oil might not be able to cope with it all for a long time. Another common error people commit is following the same regiment for diesel engines. Diesel engines exert a lot more pressure on the motor oil and that can cause it to degrade a lot faster. If your car has a simple petrol engine then the oil can last longer but if it is a more complicated system then the oil will have to be changed more often.
Is 3,000 miles a myth?
A common number floated around by manufacturers and mechanics about the optimal duration for oil replacement is 3,000 miles. This seems reasonable but in reality is a very safe number and is an overkill in most cases. There have been multiple research studies that have shown that this number is no longer relevant. Modern cars and modern engine oils are much better than what they used to be. This has resulted in them being able to withstand a more varied set of conditions for longer. If you have a newer car manufactured in the last decade, then you can go at least 5,000 miles and sometimes even as much as 10,000 miles, when driving conditions are favorable, between changes. This goes against everything that is suggested by websites, car enthusiasts and even professionals around the world. The problem is that all of this is outdated information that has no footing in today’s times. You can follow the 3,000-mile advice if your car is at least 15 years old but anything newer than that can stretch this duration to almost twice as much quite easily.
What happens when the oil isn’t changed on time?
Knowing the consequences of delaying the changing of engine oil can be the biggest motivator in making you do it on time. The problems start in stages with initially the engine suffering minor and temporary issues that can be fixed with the change of oil. If the engine is made to work beyond this stage on old oil then it will start running into major and more permanent issues that won’t be fixed even with an oil change. The first noticeable effect is the reduction of the quality of driveability of the car. It will have trouble starting and will rev inconsistently. It will begin to feel sluggish and there will be a noticeable difference in the way the motor will sound. These are all temporary issues that can be fixed with the oil change. If you let the car run then the noises will become more prominent and will transition into screeches, rattles, and bangs. The fuel economy will reduce drastically and the car will begin to behave erratically. If you still continue then black smoke will start pouring out from the back eventually leading to a complete breakdown of the motor. As you can see, there are plenty of symptoms the engine will exhibit to let you know that it is primed and ready for an oil change. This allows you to judge the frequency of oil change with considerable accuracy without having to rely on some generic number.
One thing that you have to keep in mind is that your fellow motorists are your biggest source of helpful information. In today’s internet-obsessed world, every make and model of a car has its own forum and discussion boards and you can always find helpful tidbits of knowledge here. However, the most important weapon you have are your observational skills and your instincts. Listen to your car and it will speak to you. It will take some practice but eventually, you will form that connection with your car that will allow you to know instantly when it is due for an oil change. The most important lesson, however, is that it is better to be safe than sorry and it is always a good idea to change the oil while it still has some life left in it so that the engine does not suffer any permanent damage.