Originally Posted By: horse123
No, actually.
On any normal car I guarantee you if you look in the manual it says to replace the intake air filter every 10 or 15k. Any manufacturer who lists above 20k is listening to their marketing team more than their engineers. Good luck running 30k on a car that lives on a dirt road sweety.
On a vehicle with a restriction gauge (which is how one properly ascertains when it is necessary to change the filter based on loading) it has been proven time and time again that the mileage based intervals are insanely conservative. Claiming longer intervals are based on "marketing" there honey-bunch does nothing to bolster the legitimacy of your claim.
Regarding living on a dusty road, yes, that will reduce the interval, and this is covered in most owner's manuals.
Regarding the part I've bolded and underlined:
On the E39 BMW, air filters are part of the Service II schedule, which is designed around being every 48 months or 60,000 miles, but will vary depending on fuel consumed, which is what controls the service interval notifications on 1997 and newer vehicles.
The Charger's interval is 32,000 miles or 24 months. They call for an inspection at 16,000 miles (12 months) if operated in dusty or off-road conditions.
The Expedition's interval is 30,000 miles as per Ford.
These are all "normal" vehicles. Would you like some more examples?
The 2012 Subaru Impreza:
Shows the air filter change interval at 48,000Km/30,000 miles, which is in-line with Ford and Dodge's recommendation above.
