very helpful thanks.

All, do you feel the TRD CAI still falls under a sub par filter system?

All I'll say is this. When you see dudes like the turbocharged drag guys running a simple wire mesh over the turbocharger inlet to keep out big chunks, you can immediately understand that the more air a filter lets in, the more dirt and other garbage gets in. They are largely able to accomplish this due to there usually being little to no debris on a professional drag track.

That being said, the opposite is also true. The baja guys run a filter AND a foam-type sleeve "prefilter" because of the obviously very dirty and sandy conditions in which they run their vehicles.

For what it's worth, I'll stick with the factory filters.

Why is this stickied lol I just spent 30 minutes reading 7 pages of opinions

I recommend better to buy original parts, here at first find the original part number and after try to buy it from the shops

I have been running a K&N on my truck and have been since 1974, same filter, I also have a foam cover for it when running in very dusty areas. I was not looking for any speed increase, just a better filter. About once a year I pull it and wash it and re-oil it. My Toyota will use the stock filter, I don't run that much dirt. I post this only to say there is nothing wrong with K&N's or most of the after market filters, if you take care of them.

Bump

thanks for all this helpful info. I had been running a K+N air filter in all my vehicles, including my new 4Runner... will def. be making my way back to the stock air filter though

We had a leaf in ours

Great info!

I agree! OEM FTW!

I run the K/N and aftermarket exhaust systems (mostly magnum flow) on most of my vehicles. My 08 tundra has had it since day 1 and it is a nice increase in power. Much faster than my friends stock truck both off the line and at 50+ mph . All my offroad toys from quads to canam utv run k/n filters and with the other mods they are faster and more powerful than stock. I dyno my mods because I want to see when I'm going in the right direction. The K/N air intake is 1 of the first mods we do and when combined with other mods it works well and never in 30 years have I had a issue with a motor. My offroad toys and trucks are properly cared for that is why. Clean the filter , oil it, and change your oil properly and if you do the right mods around it you will see improvements in power with no issues with correct maintenance. My old 3rd gen 4 runner is now going to some mods and the k/ n intake was the first change. The exhaust system is going in next week.

I have proof that for a forced induction vehicle, the stock paper filter is a major restriction in the intake. Peak gains of +7RWHP and +9RWTQ with filter alone (and that was AFTER heat soak set in)



However for a stock vehicle, they don't have the same CFM flow needs so there's very little power to gain, if any.

Admittedly I didn't read all 7 pages of this thread. I did read the diesel forum and 3 of the pages here. If someone mentioned this, apologies. I used to have a Buell motorcycle and did a lot of mods to it with the airbox and exhaust. Two things that I learned was 1.) an intake mod only probably does nothing - take the whole thing off before the manifold with no restriction - you still have to get all the air and exhaust down one or two small pipes. Don't try that, I'm just trying to make a point. Second thing I learned is that most modern FI systems want a 14.7:1 stoichiometric AFR. So put on a 12" intake and a 30" catback and the system just doesn't open the throttle as much for a given throttle input. The cylinder air volume (on naturally aspirated) hasn't changed, the amount you pass through the CAT (assuming its still attached) hasn't changed, AFR preference in the ECU still wants 14.7:1. The only thing I may agree with is cold (denser) air vs. sucking in hot air under the hood. Even this though won't be very much when you're driving in 115° ambient temp with 300° coming off the asphalt. Even with no CAT and a lot of intake mods., without altering the ECU, I don't see much gains happening in normal everyday driving.

If you have points or carb system... the picture is totally different.

Forced air - performance gains
Bore over stock - performance gains
Modified ECU programming - depends what was changed

Just my 4.5 cents...

Anybody running the TRD drop in air filter? Thoughts? I have one in my Tundra along with the air flow accelerator which is the first piece to the TRD cold air intake system, it basically creates a venturi effect. It is the part that air comes into from the fender.