Mileage has nothing to do with starter life... well, a little.

But what does affect starter life is how many times it's started, and how easily the car always starts.

For instance, if you deliver pizza and you shut the car off after every 2 miles and re-start.. that's 50,000 starts/100,000 miles.

If you commute to work 100 miles/day and only use the starter that often, it's only 1000 starts/100,000 miles.

If you live in California where it's always 72° and your car is in perfect tune and starts instantly, every time... started don't take much wear.

If you live in Alaska and have to crank the thing for 10 minutes to get the car to start when it's 40° below zero... well then, that starter ain't gonna last as long.

All that said, I'm guilty of all the cited starter abuses, and I'm pretty sure my starter is original at 325k miles.

Don't worry about it unless it becomes a problem.

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-Matt I ♥ my ♂