75k is not high miles for an engine that has had oil changed regularly. I know there are some people out there that buy a car and never change the oil, in which case 75k can be high miles. I didn't go to a High Mileage oil in my Camaro until 150k, and that was mostly to get the higher zddp level of an SL oil. A side benefit was that it slowed oil consumption by ~25%. I think the decision to go to HM oil should be driven more by a desire to reduce oil consumption or seal seepage than by what the odometer says.
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