Is it usual for a belt tensioner to go off centre and shred the belt? This was the case with our Peugeot 3008 at 28,000 miles.

Many modern passenger cars have either a timing belt or a timing chain. Generally speaking, timing belts have the advantage of being quieter and cheaper to produce and replace, while timing chains ...

A belt sitting in a dealer's warehouse isn't subjected to the stresses and strains of a belt that's in your car, so it wouldn't be unserviceable as you contend. Belts do deteriorate in the rather ...