Low mileage, engine air filter change frequency?

[Flycaster]

Just went off 4 year BMW warranty. My 4 year old 2005 2.5l Z4 has 17.5K miles. No real hard driving. Driven in south Florida. How often should I be changing the engine air filter?

[em2b96p]

once... get an K&N air filter... i believe the part number is 5070? im too lazy to search.

when i installed mine, my AC smelled like the filter oil

[Flycaster]

Originally Posted by em2b96p

once... get an K&N air filter... i believe the part number is 5070? im too lazy to search.

when i installed mine, my AC smelled like the filter oil

Not sure what you mean about the filter oil smell. Doesn't sound good to me. Also, I've read the the K/N filters are nice, but they really, from a tested point of view, don't do much for the car, but certainly are more expensive that any good quality filter.

[caseysc]

Originally Posted by Flycaster

Not sure what you mean about the filter oil smell. Doesn't sound good to me. Also, I've read the the K/N filters are nice, but they really, from a tested point of view, don't do much for the car, but certainly are more expensive that any good quality filter.

+1. Stick w/OEM filters.

[jmillet]

Originally Posted by Flycaster

Just went off 4 year BMW warranty. My 4 year old 2005 2.5l Z4 has 17.5K miles. No real hard driving. Driven in south Florida. How often should I be changing the engine air filter?

Per the BMW NA Service Maintenance Checklist for your Z4 replacing the intake air cleaner element (AKA air filter) is an Inspection II item which translates into about every 40,000 miles. The checklist does say:"Reduce replacement interval in dusty operating conditions"
Best practice is to open up the air box at every oil change and examine the filter. Clean all the debris out of the air box and vacuum off the filter. If the filter is still showing signs of being dirty then replace it. I'd stick with the OE paper filter P/N 13 72 1 744 869 that will run you $13.78 from Autohaus AZ.
Don't forget about the cabin filter P/N 64 31 6 915 764.

[AWM3]

Originally Posted by jmillet

Per the BMW NA Service Maintenance Checklist for your Z4 replacing the intake air cleaner element (AKA air filter) is an Inspection II item which translates into about every 40,000 miles. The checklist does say:"Reduce replacement interval in dusty operating conditions"
Best practice is to open up the air box at every oil change and examine the filter. Clean all the debris out of the air box and vacuum off the filter. If the filter is still showing signs of being dirty then replace it. I'd stick with the OE paper filter P/N 13 72 1 744 869 that will run you $13.78 from Autohaus AZ.
Don't forget about the cabin filter P/N 64 31 6 915 764.

What he said.

It's just folded paper with a plastic frame. It would last 40 years if you only drove 1000 miles per year. K&N are not recommended because the oil can foul the airflow meter and cause problems. The factory paper filter is just fine. If they could have claimed 5 or 10 more HP by changing the paper filter, with all the millions they spend on engineering, don't you think they would have done so? It's not the limiting factor in airflow or HP for the engine. Dyno testing with different filters or no filter at all indicates no difference in engine power.