I have a 93 that for some reason uses 92 front pads. Here's my mileage for replacements over the past few years. I always use factory pads and I don't drive aggressively. I change the pads as soon as I get the indicator light.

148,500
179,007
195,075
210,493
228,947
252,502

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1993 400E, 256,000 miles (totaled)
1994 E420, 200,000+ miles
1995 E420, 201,000 miles