We all know that our cars need an oil change at some point, but how often should it be done? The answer can be confusing, as it varies depending on driving conditions and habits. Let’s simplify it for you.
In the past, conservative estimates for oil change intervals were as low as 5,000 kilometers. However, with significant improvements in fuel delivery systems, engine materials, manufacturing methods, and oil chemistry, modern engines typically extend oil change intervals to 10,000 or even over 15,000 kilometers. So, what is the correct answer?
When Your Car is Under Warranty
For new vehicles, the answer is simple: follow the oil type, mileage, and change time recommendations in the owner’s manual if you want to maintain your powertrain warranty. In most cases, you’ll bring your vehicle to the dealership for required inspections and maintenance, and oil changes will be included in those operations.
Some newer vehicles have a built-in oil life monitor. This device uses an algorithm, sensors, and software to track operating temperatures, cold starts, driving hours, idle hours, and engine revolutions. It uses this data to calculate the oil condition and change intervals that preserve the warranty. Keep in mind that the oil monitor is calibrated for the recommended oil type in the owner’s manual. Service alerts are displayed on the instrument cluster, which, in some systems, will show the remaining oil life as a percentage. This is very different from the red oil pressure warning light that comes on when starting the engine. If it illuminates while driving or idling, it means you either have no oil or a serious problem with the engine. It’s time to pull over and turn off the engine.
When Your Car is Out of Warranty
Once the manufacturer’s warranty has expired, determining oil change intervals requires some common sense and an educated guess, unless your car has an oil life monitor. There are often different recommendations for normal driving and severe or intense driving. Intervals can vary widely depending on whom you ask, whether you tow (and how often), the time of year, and even the driving conditions. By the way, as the cold temperatures approach, it’s a good idea to prepare your car for winter.
Severe driving includes:
- Taking many short trips of 10 kilometers or less (in normal temperatures)
- Taking many short trips of 15 kilometers or less (in freezing temperatures)
- Stop-and-go driving in extremely hot climates
- Driving at low speeds for long distances
- Driving many kilometers on dusty, muddy, salty, sandy, or gravel roads
- Towing for long distances
- Track driving
Is it Better to Change the Oil Frequently?
It’s not surprising that service providers (oil change shops and dealerships) tend to recommend shorter oil change intervals (5,000 to 10,000 kilometers). This can never harm your engine, but it also means they will see you and your credit card more frequently. When a car is on the lift for an oil change, other worn-out components such as brake pads, coolant, tires, and shocks can also be evaluated and possibly replaced. So, it’s obviously good for you too. (For older vehicles that may burn oil, you’ll want to check the fluid level with the dipstick at least once a month). However, if you don’t drive your car in severe conditions, and few of us do, you can stick to the manufacturer’s recommended oil change intervals (which often include an oil filter change at the same time). And of course, if your car has an oil life monitor, pay attention to it. By the way, do you know how to check your car’s oil?
Extended-Life Oils
What about using expensive extended-life premium synthetic oils for projected intervals of 15,000 or even 20,000 kilometers? Regarding synthetics: almost all newer vehicles use them, so if the manufacturer specifies it, you should use it. Many older cars were not filled with synthetic lubricant when new and still use conventional petroleum-based oil. In that case, you have another option.
Some oil refineries produce sophisticated extended-life oils approved by car manufacturers that help extend the time between changes. These oils have special chemistry or additives that support their ability to go longer distances. They better resist decomposition at high temperatures and keep dirt and particles in suspension for longer, allowing the oil filter to catch them. They also cost more than standard oils, so you’ll have to do the math to see if the additional cost is worth it.
Precautions
If you drive on dirt roads or in dusty or salty environments and make many cold starts and short trips, the factory oil filter has little filtering capacity. (That’s why most manufacturers recommend replacing the filter with every oil change). Additionally, extended-range oils can be contaminated by the high volume of combustion gases passing through the worn piston rings of older cars. Eventually, the oil no longer protects the sliding surfaces inside the engine as it should. Engine wear accelerates after the oil breaks down or becomes heavily contaminated. And lastly, almost no car manufacturer recommends leaving oil in the crankcase for more than one year, regardless of mileage.
Oil Recycling
If you change your own oil, be sure to recycle it properly. Most auto parts stores (check before buying) and oil change companies accept used oil free of charge. Whether you do it yourself or have it done for you, changing the oil at the proper intervals will make your engine last longer and run better. By the way, do you know what the oil viscosity index means?
FAQs
How often should you change the oil in months?
It depends on the manufacturer. The traditional rule was every three months, but with improvements in oil quality and engine materials, that interval can be extended to any period between six and 12 months. The owner’s manual will detail the interval.
What happens if you go too long without an oil change?
As the oil quality wears out, so do the components it’s supposed to protect. If you go too long between oil changes, you’ll reach the point of no return, and your car’s engine will become a major repair bill or even a total loss.
Can I change the oil every two years?
No. Almost no car manufacturer recommends leaving oil in the crankcase for more than one year, regardless of mileage.
How do I know when I need to change my oil?
Usually, you follow the mileage and time intervals indicated by the vehicle manufacturer. However, this can vary depending on the intensity of your driving. As mentioned before, shorter trips, track time, and dusty roads can cause the oil to break down faster and require an earlier change.
Some vehicles have information displays on the instrument cluster that will read the remaining oil life as a percentage. If it doesn’t have this feature, follow the oil change label or keep track of the mileage yourself. Don’t forget to check the oil with the dipstick at least once a month. By the way, do you know what type of oil your car takes?