Oil changes are the essential routine maintenance that needs to be performed to ensure the smooth operation of a vehicle's engine. However, it can be confusing to know when you should change your car's oil.
There is the conventional advice that has been passed from one generation to the next over the decades. Then there is the modern advice that contradicts the traditional advice. So how do you know when you need an oil change? The first place to look is your vehicle's owner's manual, which will not only tell you the recommended mileage interval, but also the type of oil (or weight/viscosity) that is best for that particular engine.
Oil Change Intervals for Newer Cars
Newer vehicles do not require oil changes as often as older vehicles, thanks to modern innovations and development. The metal parts in the engine are built using more precise manufacturing techniques. It allows the components to operate with one another without catching or wearing unevenly.
Because of these advancements, and with the use of modern synthetic motor oils, modern engines now have recommended oil changes only every 5,000 to 7,500 miles; some might go as long as 12,000 - 15,000 miles. The additives in synthetic oil extend the life of the oil by making it more resistant to high-temperature breakdown. They also help the oil suspend particulates, debris, and dirt better so that the oil filter is more effective at catching them as the oil flows through the filter.
Oil Change Intervals for Older Cars
Older cars will have oil change intervals based on mileage. There will be two oil change schedules in the owner's manual. There is the "normal" use and the "severe" use schedule.
Those that fall into the severe use schedule experience these types of driving conditions:
- Towing or hauling heavy loads
- Extremely hot, dusty, or cold climates
- Mainly short trips that are less than five minutes
- Primarily stop and go driving.
Older cars also use conventional oil, which means it needs to change more often. It's where the standard 3,000-mile interval originated. Older cars did not go through the same precise production methods that modern cars experience today. That means that the metal parts are not as precisely machined and need motor oil to prevent engine wear.
As the engine ages, the metal parts rub against each other and create wear. It helps to change the oil more often and to use a specially formulated high mileage oil to protect an older engine. Since older engines were not manufactured to use synthetic oil, you have the option of continuing to use conventional oil. However, an older engine might operate better when switched to synthetic.
Oil Life Monitoring Systems
Oil monitoring systems have also become more advanced. The oldest of cars has no oil life monitoring system. Then cars had simple monitoring systems that would alert owners of a needed oil change based on how many miles you drive the vehicle.
The newest cars on the road have advanced monitoring systems that use algorithms to determine the remaining oil life. Several sensors throughout the vehicle monitor the operating conditions. A computer then uses this data to determine the oil's remaining useful life.
It's eliminated the need to provide "normal" and "severe" interval schedules. The monitoring system will automatically adjust to shorten the oil's useful life when more severe driving conditions are detected.
For the monitoring system to work, the dealership technician will reset the monitoring system when the oil gets changed. If you perform oil changes yourself, you will need to do this reset with a special tool found at some auto repair shops or online.
Manufacturer Warranty Coverage
If your vehicle still has coverage under the manufacturer's warranty, you will need to follow the oil change maintenance schedule laid out in your owner's manual. Otherwise, you risk voiding the powertrain warranty. You will need to follow the mileage interval and type of oil recommended.
Most new car owners will take their vehicles to the dealership for required routine inspections and maintenance. The dealership will check the oil and recommend an oil change when necessary.
How Driving Habits Affect Oil Change Intervals
The standard oil change intervals are good to follow when you have normal driving habits. However, if your driving habits fall outside of typical use, you will want to factor this into your oil change routine.
Car experts recommend more frequent oil changes when you put your engine through more stressful driving conditions. When your engine works harder, your oil life decreases. To maintain your fuel economy and engine performance, you will need to change your oil more often.
Another dilemma car owners face is when they do not use their vehicles very often. Because most oil change intervals are based on mileage, this can lead you to believe that you will rarely need to change your oil if you do not drive much. However, this is not entirely true.
If you rarely drive your vehicle or barely put miles on it, then you should plan to change your vehicle's oil every 12 months. Oil ages over time even if you are not driving. Changing your oil once a year ensures it is effective when you do decide to use your vehicle.
What Happens When You Wait Too Long
As you drive your vehicle, the oil ages and eventually becomes less effective at lubricating and protecting your engine. Waiting too long to change your oil increases the wear and tear on your engine, causing it to age prematurely.
The increased friction causes the engine to get hotter than it should. Your engine will not run as efficiently as it should, and your fuel economy will drop. If you continue to avoid changing the oil, you will eventually cause permanent damage to the engine. That can be expensive and, in some cases, exceed the value of the vehicle.
Check Your Car for Its Next Oil Change
Once your car is no longer under warranty, you will need to use common sense when changing your vehicle's oil. You could follow the manufacturer's recommendation that's outlined in your owner's manual. Most vehicles will have you warm up the engine to operating temperature and then turn off the engine.
Pop the hood and look for the dipstick (the long metal piece that you pull out of the engine and use to check the oil level and cleanliness). It will have a pull tab that may even be colored so you know what to look for. Wipe it off and reinsert it all the way back in. Pull it out again and inspect it.
If the engine oil level read low on the dipstick's markings, then it is time to change your oil. If you're doing it yourself, let the engine cool and drain the old oil from the vehicle. Replace the oil filter and add new oil.
Extend the Life of Your Vehicle
As you can see, it isn't enough to know that you need to change your vehicle's oil. If you want to get the longest useful life out of your car's engine, you need to change your oil regularly. The answer to how often you need an oil change will depend on the age of your vehicle, the type of oil it uses, and your driving habits.
A good rule of thumb is to start with your owner's manual recommended interval and then use common sense and monthly checks to determine the best interval for your vehicle. The more extreme your vehicle use, the more often you should change your oil. If you barely use your car, you should change it at least once a year.
All of these tips should help keep your vehicle in good working order, ensuring mostly trouble-free maintenance for thousands of miles.