On the Lexus LS 400, the timing "Belt" change frequency is 120,000 miles.
On a Nissan Maxima the timing "Chain" life is 200,000+ miles.

If Mercedes Benz timing "chain" needs to be changed after 100,000 miles, then it is a poor design, similar to other poorly desgined area's like radiator neck, AC Evaporator, Head Gasket........

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Zafar
94 E320 58000 Miles