Back in the day it was always supposed to be every 12k miles or so, does that still hold true?

What brand is everyone using?

 

12K? Maybe if the environment you drive in is very dusty, otherwise it is every 30k. I usually buy whatever is cheapest, not like the engine needs quality HEPA type filter, just want to filter out dust particles. The cabin air filter might need changing every 20-30k.

 

scroll down to page 51

http://www.lexus.com/pdf/service/CTh_WSG.pdf

 

(for the lazy people ... the answer is 30k)

 

I currently have a K&N air filter (part# 33-2435) and clean it every 20K miles. I have noticed better mpg's and performance using the K&N air filter.

If I had the paper filter I would replace it every 30K miles. I personally would purchase the OEM Toyota/Lexus air filter (part# 17801-37021) or a high quality air filter such as Wix (part# 49320).