Air Filters... K&N or TRD?

[Virus18]

The actual standardized tests that K&N run are a completely different test than those listed on almost all other filters. The test they run test larger sized particles which of course will be stopped by the filter and therefore produce great looking percentages, when in fact they let alot through. Oil analysis run on those that have added K&N filters, including myself, always show much higher silicon numbers. www.bobistheoilguy.com is a great resource.

[Virus18]

Although not a direct drop in, here is a filtration article done showing filtration of many high performance filters.

http://www.mkiv.com/techarticles/filters_test/2/

[njerald]

The only way to increase air flow thru an aftermarket filter that has the same surface area as the factory filter is to increase the filter's open area.

More open area lets more airflow and more dirt thru.

More dirt equals more wear.

[tzeshan]

I need to update my experience with the K&N air filter. Because I feel I owe an apology to K&N. I have posted a reply after the first tank of gas after replacing with the K&N air filter. I said I did not notice any improvement in MPG and it may actually be worse. I got less than 25 MPG for the first tank. Now I have new data from the second fillup. I get 26.2 MPG! This is 4-5% improvement. Although the weather is warmer for the second tank, but at the same time last year I got 25 MPG. It seems to me the first tank is low may be due to the drive-by-wire feature of this car. The car reset its drive-by-wire at each fillup from the performance of previous tank of gas. The first fillup, the car did not know it has to reset its parameters. At the second fillup it knows how to reset. This explanation is all guessing.

[njerald]

Originally Posted by tzeshan

I need to update my experience with the K&N air filter. Because I feel I owe an apology to K&N. I have posted a reply after the first tank of gas after replacing with the K&N air filter. I said I did not notice any improvement in MPG and it may actually be worse. I got less than 25 MPG for the first tank. Now I have new data from the second fillup. I get 26.2 MPG! This is 4-5% improvement. Although the weather is warmer for the second tank, but at the same time last year I got 25 MPG. It seems to me the first tank is low may be due to the drive-by-wire feature of this car. The car reset its drive-by-wire at each fillup from the performance of previous tank of gas. The first fillup, the car did not know it has to reset its parameters. At the second fillup it knows how to reset. This explanation is all guessing.

Guessing is one word for it................

[tzeshan]

One more thing, the trip computer was known to over estimate the MPG by more than 1 MPG. But this time it is very close to my calculation. Again, I "guess" the trip computer may be calibrated by Toyota engineers with the optimum condition. They may actually used a K&N air filter.