I recently purchased a used 2012 Volvo XC70. It has a diesel engine and the start-stop function. Both the salesman and later my mechanic told me the same thing - this feature wears down the starter quickly and I'm better off by turning it off. However I'm a bit skeptical about this and suspect that they simply might have some old habits.
I googled around about this but couldn't find much solid information. Some sources claim that the start-stop starters are different than normal starters and are designed for such loads. Others say that the starter will wear down more quickly. So which is it? Does the start-stop function wear down a car's starter faster, or is the starter specially built for this and will not need replacing more often (if ever)?
Some more notes:
- While I am, of course, most interested about my specific car, this site welcomes more generic questions if possible. So ideally I'd also like a more generic answer, not tied to a specific make or model. However I can totally understand that for different manufacturers the answer may vary, so - the more information, the better.
- I'm not questioning whether the system actually achieves any fuel efficiency. That's a separate question that I'll seek to answer with my own observations in the coming months.
- Neither am I asking about battery wear. Obviously such a system places greater load on the battery, which is why AGM batteries tend to be used. For some cars (mine included) there's even a smaller secondary battery just for the start-stop system. It's understood that this battery will most likely wear down much faster (probably lasting only a couple of years), however replacing that is much easier and cheaper than replacing the starter, so it's not such a big problem.