So i lived in seattle and with all the rain there is little dust. I could go 15K miles and it would still be fine.
Here in MX i live 15 miles away from Popocatépetl which over the past 2 months has been erupting and dusting everything with ash (like cement) about twice a week. plus its dusty here this time of the year. I replaced about 3k ago and i pulled it off today to check it and it was way past due with my secondary filter all dusted up. That got removed.
Granted these conditions are extreme but what is everyone who lives in dusty contitions doing. I did the local filters and bumped it up to toyota which seems marginally better. Ill go with an aftermarket as soon as i get back to the US for a trip i need to do but was just wondering -- what every 1k miles?????. or is a little ultra fine dust past the filter ok and normal in conditions