I wish I still had the promo material for the brilliant zetec/yamaha engine when it came out. It originally promised the belt was, "for life" although later this was changed and replacement recommended in every reducing intervals. Still plenty of used and abused examples around well over 150,000 miles and appear to suffer no ill effects.

The new ecoboost engine will really frighten the luddites though. Buried deep in the engine and actually running through the oil-filled sump!