Modern car odometers can record up to a million miles driven. What happens to the odometer reading when a car drives beyond its maximum reading?

Unless the odometer has been tampered with, nothing happens to the odometer reading when a car drives beyond its maximum reading.  It will continue to read and show the mileage the car is covering.  The odometer is simply indicating that the car has reached its useful life and needs to be replaced by the user or owner.

Explanation:

Ordinarily, the odometer is installed to show the car's mileage.  It also indicates when some maintenance and repairs must be carried out.  Attaining the maximum mileage shows that the car is too old for continued maintenance because the car has experienced much wear and tear.  Many of the drive belts and pumps will require replacement if one must continue using the car at this point.  The costs of servicing and repairing the car will skyrocket to uneconomical levels.

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