Every couple of months, car owners run into the same perplexing question: regular oil or synthetic oil? Does it matter? Which is more cost-effective? Why do cars even need oil changes in the first place?

Why Change the Oil?

To answer the most basic question of why cars need oil changes, it’s important to first understand what oil does in an automobile. It lubricates the internal components of the car’s engine, and provides a cooling effect to prevent engine overheating. It’s important to remove the old, dirty motor oil and replace it with fresh oil because the properties of the oil change with time and use.

Over time, oil can form sludge in the engine, which can reduce the efficiency and even the lifespan of the engine. As it breaks down, it also starts to allow the moving components of the engine to rub against one another. The engine parts begin to wear without the protective lubrication wear on the engine parts, also decreasing the life of the engine.

Which One to Choose?

Conventional oil costs less than synthetic oil, but also must be replaced more often. Conventional oil should generally be replaced every 3000-5000 miles, while synthetic oil can be replaced every 10,000-20,000 miles, depending on climate, driving distances, and the type of synthetic oil. The automobile owner’s manual generally gives factory recommended mileage and timing for oil changes.

While the lower price of conventional can be tempting for all drivers, there are some factors to consider:

• Make, model, and year of the car. Many modern cars are actually requiring use of synthetic oil in their engines.
• Wear and tear. If the car is driven long distances and used frequently, synthetic oil may be a better choice, as it is more durable, thus more protective against engine breakdown and less likely to cause engine sludge.
• Extreme temperatures. Synthetic oil is designed to withstand both cold and heat without breaking down. Car owners who live in cold climates may find that synthetic oil is more fluid in icy weather, so that it can better lubricate engine components. It is also more durable in the extreme heat of the engine. Carrying or towing heavy loads can increase the temperature inside the engine even more, making synthetic oil a better choice for vehicles that do a lot of hauling.
• Time. Car owners sometimes choose synthetic for the sole purpose of efficiency. It can take a lot of time and effort to take each car in the household in for an oil change every three months. Choosing synthetic oil can enable car owners to go half as often for an oil change—or even more.

Personal preference, driving habits, climate, and type of car should all be taken into consideration when deciding on conventional or synthetic. But whichever one you choose, be sure to get your oil changed—don’t let busyness or forgetfulness get in the way of keeping your engine clean and lubricated!