Why are oil changes so important? Car oil is vital to the function of a car and acts as a lubricant for your engine; it allows metal to converge with metal without causing damage. For example, oil lubricates pistons as they move inside the cylinders. Without good, healthy oil, this friction can create such intense heat that the surfaces can eventually weld together—a situation that would give your car’s engine the inability to function.

Old Oil: What’s the Worst That Could Happen?
Your car’s engine, and many of its parts, will suffer and could ultimately face failure if you avoid or delay your oil change. Although your car isn’t necessarily at risk if you’re overdue a mere few hundred miles, but you could face catastrophic effects—even vehicle failure—if you exceed your oil change by several thousand miles.

• Dirt will accumulate in the oil. Your car’s filter will continue to function and remove dirt for a while, but over time, the filter will become clogged and oil will bypass the filter. Thick and abrasive, dirty oil causes greater wear to a vehicle.
• The oil can’t lubricate the car. When detergents, rust-fighters, friction reducers and other additives in the oil deteriorate, the oil isn’t able to lubricate the car’s parts properly.
• Your oil can turn into sludge. When left unchanged, oil can turn into harmful sludge that causes major engine problems. This sludge can cause an engine to run incorrectly or even seize.