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How Often Should You Change Your Oil?

By Autolist Staff | May 9, 2019

How Often Should You Change Your Oil?

Conventional wisdom tells us that our cars need a fresh oil change every 3,000 miles. And this was true of most vehicles at one time. However, with changes in engine design and the emergence of modern lubricants, it is not unusual for a car to go much, much longer before needing an oil change. In fact, for engines that use full synthetic oil, it is possible under the right circumstances to avoid an oil change for up to five times the traditional recommendation. No matter the vehicle, the interval between oil changes depends on the age of the car, the type of oil used, and the driving conditions that the vehicle regularly undergoes. Let's look at what all car owners need to know about oil change intervals so that you can be sure your vehicle gets the TLC it needs to run its best.

Oil Changes for Older Cars

The traditional 3,000-mile oil change rule was a typical recommendation years ago when oil change intervals were based mainly on the number of miles driven. But much like those old clunky car phones and cassette tape decks in older cars, recommendations change. Cars from about 2007 and earlier that are used for normal driving conditions, most experts now recommend changing the oil every six months or 5,000 miles, whichever occurs first.

Typically, an older car has one of two possible maintenance schedules: one for vehicles driven under normal conditions and one for cars that are operated in more extreme conditions, such as in severe weather or under lots of heavy acceleration or hauling. Harsh driving conditions include being driven primarily for short trips of five miles or less, driven mainly in stop-and-go situations, towing a trailer or carrying heavy loads, or driving in a climate that is extremely dusty, hot or cold. If you frequently drive your car under severe service conditions, then you will need to go by the standard rule of changing the oil every three months or 3,000 miles. The owner's manual for your older car will help you determine the best oil change interval and engine oil type for your particular vehicle.

Oil Changes for Newer Cars

New cars (from 2008 onward) generally have greater oil change intervals than older vehicles due to their use of synthetic blend, multi-grade, low-viscosity, and other newer generation resource-conserving motor oils that maximize a car's fuel economy and minimize friction. These motor oils are formulated to last longer before viscosity breakdown when compared to old-school 10W30, 10W40 and so on, thus their longer service life.

The number of miles you can drive your late model car and the expected oil life for your new car is generally mentioned in your owner's manual. These figures can vary widely. For example, Toyota Camry 2.5-liter 4-cylinder models go typically 10,000 miles between oil changes. BMW cars that use synthetic oil can go up to 15,000 miles. New car oil changes require that the proper oil is used, based on the model and make of the car; it must be the correct SAE viscosity grade and automaker's recommendations.

Oil Life Monitors

If your vehicle is equipped with an oil life monitor, it is easy to determine when your car is due for an oil change. These monitors come on many modern vehicles from major manufacturers, and they base their recommendations on things like the number of cold starts, climate conditions, engine temperatures, and vehicle speed. Some owners of vehicles equipped with such monitors have indicated that their vehicles' monitors sometimes suggest that they can safely drive even more miles past the recommended intervals for changing the oil.

Why Do Oil Changes Matter?

Motor oil’s significance cannot be underestimated. Just like the blood that runs through your veins has important jobs to do in your body, the oil in your car has many vital tasks. Your car’s oil cools and lubricates the hundreds of moving parts that keep your vehicle in good running shape. It protects the car’s engine, preventing contaminants and dirt from forming sludge that can result in engine wear, potential damage and reduced performance. It seals off gaps, reducing contamination by unburned fuel and water. Motor oil also prevents corrosion due to acid or moisture that might otherwise make their way into your car’s engine.

Due to the constant work that motor oil does in your engine, it gets dirty. Moreover, once motor oil is “spent,” the additives in the oil that power its magical ability to keep your motor running become depleted. These additives include anti-wear agents that form a protective coating with metal surfaces to protect the life of your engine. Detergents that reduce the formation of contaminants and inhibitors that prevent corrosion and rust from forming are also depleted. They can lead to your vehicle experiencing breakdowns in the components of the engine. The oil’s friction modifiers also become depleted over time, which results in reduced fuel economy. And last but not least, viscosity index improvers in the oil are reduced, resulting in thicker oil that doesn’t do its job as efficiently.

"But My Quick Lube Guy Recommends It"

Well, of course, he does! Your friendly (and perhaps, well-meaning) oil change guy may still stick wholeheartedly to the old recommendation of changing your oil every 3,000 miles. They may also do a good job convincing you that your car needs these frequent oil changes. It is, after all, in their best interests. Oil changes are his bread and butter. But bear in mind that your best resource for determining how often to change your oil is the manufacturer of the vehicle. The manufacturer is vested in keeping your car running great for as long as possible. The automaker wants you as a repeat customer and doesn't want to pay for any repairs that fall under your warranty. For these reasons, the manufacturer's recommendations should trump those of Moe the Mechanic downtown.

The Bottom Line

Not all cars need to have their oil changed every 3,000 miles. And most car makers agree, according to research conducted by Edmunds. Automakers are now recommending, for the most part, that cars have an oil change between 7,500 miles and 10,000 miles. One big name in the industry, GM, suggests changing the oil at least annually, even if the oil service indicator warning never flashes. Although you can't harm your car by giving it a fresh oil change before its need for one, it can be a waste of money. Not to mention that it is also bad for the environment since that old spent motor oil has to be disposed of or recycled when it was still useful for many more miles.

Nonetheless, if you are a staunch believer in frequent oil changes, then the thought of driving your car for 15,000 miles without one may not sit well with you. But perhaps there is an excellent middle ground. Some experts say to have your oil changed whenever you take your car in for a tire rotation. That gives you a chance to kill two birds with one stone while having peace of mind that you're giving your car's engine the lifeblood it needs to be its best.