Most cars today have a cam belt which requires replacing every few years as per the manufacturer’s recommendations to prevent a costly vehicle breakdown. Alternatively, some vehicles have timing chains, although these are less commonly seen these days, which do not require replacing as often, however they do wear out over time so eventually replacement will be necessary.
Although some people put off getting a cam belt replacement in an attempt to save money, if it should snap the damage to the vehicle can be quite extensive and costly to repair, making replacement a much more cost-effective option overall.