eli5: How do car engines last so long?

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A car engine basically has thousands of mini explosions happening inside of it, is has parts moving very fast and generating tons of heat, and experiences extreme temperature fluctuations on a daily basis. Yet it is the part that usually dies last in a car.

How do they make them last so long and why are we unable to make other parts of the car as long lasting, such as tires and brakes?

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21 Answers

Anonymous 0 Comments

Most of the answer is oil. There’s a thin film of oil that separates the moving parts of your engine and reduces friction to almost zero. The heat is mostly absorbed by engine coolant (antifreeze), which is then cooled by the radiator.

By contrast, your brakes operate by taking the car’s kinetic energy and turning it into heat. They do that by rubbing two materials together, which naturally causes wear and tear. Some electric vehicles are changing that with regenerative braking, but most brake systems just have to wear out in order to function.

The tires also operate by rubbing on the pavement to make the car start, stop, and turn. There’s no real way to prevent wear on them, because that’s just how they work. If you put a film of oil on your tires, they wouldn’t wear out as fast, but your car wouldn’t be controllable.

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