Which traditional time based scheduled maintenance items are valid? I ask because my 1999 Toyota OM says time intervals are based on the assumption that people drive 15k miles per year. E.g., Toyota says replace coolant every 24 mos or 30k miles. Surely coolant does not significantly degrade in a sitting car. I now believe Honda makes the same assumption. Honda used to specify 7yrs/105k miles for timing belt. When the MM was introduced, Honda no longer specifies time based maintenance except to replace brake fluid every 3 years. Since the MM does not count time, Honda owners do not get a MM prompt to change TB until 105k miles. I believe Honda carefully reviewed their scheduled maintenance when they introduced the MM and concluded the only necessary time driven item is brake fluid. If Honda engineers thought TB's needed to be replaced at 7 years independent of mileage, they would have added that footnote. After all, a broken timing belt does far more damage than 3 year old brake fluid. Acura/Honda dealers still recommend 7yrs/105k miles which I believe is driven only by profits.
So, what scheduled maintenance items are truly required based on time, independent of mileage? Thanks.
So, what scheduled maintenance items are truly required based on time, independent of mileage? Thanks.