Why your car engine loves regular oil changes

Any time your engine is running, there are parts inside it moving at several thousand times a minute, and with little more than the width of a human hair separating them from other components. Without sufficient oil for lubrication, the engine will quickly seize and become irreparably damaged.

“Engines heat up as they operate, and metal expands, so if you didn’t have oil, the heat would cause the metal parts to contact,” says Sean Martell, category business manager for oil and oil change at Canadian Tire. “Oil protects engine parts from wear, it helps take heat away from the engine so it can operate at a consistent temperature, and it captures dirt and debris that gets into the engine.”

Oil contains additives and antioxidants to help protect your engine, but these eventually break down. Changing the oil at regular intervals helps to prevent premature engine wear.

Whenever the engine is running, oil is circulated through it by an internal oil pump. It passes through the oil filter, a canister that’s screwed onto the engine, which traps larger dirt particles suspended in the oil. The filter is disposable and should be replaced with every oil change.

Having the right amount of oil in the engine is important, too. Too much can be just as bad as too little, since the oil will foam and won’t provide proper protection.

It’s best to follow the oil change schedule recommended by the manufacturer for your vehicle. “If you go a little past your interval, the oil doesn’t stop working, but it does lose its capacity,” Martell says. “In the owner’s manual, there’s usually a standard schedule and then one for ‘severe duty’ (which is more frequent).

“It’s not that severe, and over 80 per cent of Canadians drive in what is considered severe duty, including a range of temperatures, a lot of stop-and-go traffic and short trips, and a mix of dirt and paved roads. All of these put more stress on the engine. There’s no harm to your car by changing the oil more frequently, but if you follow the directions, your engine will last for a longer time.”

Things to note

Rating system. Engine oil is rated by its viscosity, which is how thin or thick it gets with heat or cold, and there are blends rated for winter or summer temperatures.

Synthetic. This oil is formulated for better flow and engine protection. It also usually has longer change intervals, and in some cases can improve fuel economy.

Thorough check up. During an oil change, the technician should also check your vehicle’s belts, hoses, tires, fluid levels, and brake pads to be sure they’re in good condition.

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