I'm also interested in your thoughts on this upgrade. Why would you recommend it? Increased mileage? Better performance? I've never upgraded an air filter before (just replace the stock filter each year and call it good). Not against it, just curious what advantages it offers...
IMO, just swapping the factory air filter out for a K&N is a bit overrated. The biggest advantage of it is you have a one time buy vs replacement every 10-15k miles on avg. Instead of toss and replace, you go to wash and oil and reinstall. The K&N alone isn't going to offer noticable gains, restrictions will still be there in both the intake and exhaust. Upgrading to a non-restrictive cold air intake system will have slightly better gains, but until you upgrade thw exhaust to a more free flowing one the full gains won't be noticed. Depending on the CAI set up you also take a chance of sucking in water during rains or off roading as well, i haven't ever looked into one to see how the Tacoma's are routed set-up. $4-600 for an arguable 15hp gain with a complete intake/exhaust upgrade really isn't worth it to me. Averaging avout 6k a year on my vehicles it would take nearly 10 years replacing the OEM filter before I seen any type of saving. Fuel mileage increase is as hard to prove/disprove as seat of the pants horsepower gains.
