Why do carmakers use cam-timing belts instead of chains?

THERE have been, and are, other means used to drive the camshaft. Holden, for instance, used gears to drive the camshaft on its early six-cylinder engines. Chains have also been used. Chains last longer, but can be noisy. Most carmakers moved to belts because they were cheaper than chains and quieter. And you might think they also reckoned their dealers could make some money through regularly replacing them.