Ask a mechanic friend how often to do an oil change and they will 9 times out of 10 give you an answer without asking what model of car.

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giobox 3 hours ago | parent [-]

I can’t say I’m in the business of asking 10 or more friends to confirm this, but any number they provide without knowing the car is a guess at best, and likely erroring on side of caution. A Google search with the car model in the query virtually always returns the correct figure ranges for said car.

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jdsully 2 hours ago | parent [-]

Ah but see the most important piece of information is not what the manufacturer specifies. Most mechanic friends would tell you manufacturers are over-extending the interval to make their cars look good to purchasers and because they only care about getting to the warranty end not total life of the car. While 3k miles old wisdom is out dated, if you do your own oil changes you can see a massive change in what comes out after 5k miles.

By over specifying the question you will miss out on the more important context.

	▲	giobox 2 hours ago \| parent [-]
		Much of what you say is true, but again your mechanic friend can only provide a meaningful answer if they know the model of car. It’s the first question any half way competent mechanic will ask! The cars sitting outside my home vary in oil service interval by over 10k miles, as just one simple example, and I don’t drive anything particularly exotic. By under-specifying the question, you rob it of the context to be answered accurately.