I see a lot of folks arguing this CAI or that CAI, but let's be honest it's not a CAI unless it's drawing air from outside the engine bay. From this perspective the stock airbox or a TRD CAI would probably in fact be the best CAI for the 5.7 Tundra. A lot of guys even mod the stock airbox and I'm sure the TRD box too, doing charcoal filter deletes and getting different drop-in filters, some N/A guys also do the TB screen delete like the S/C guys. All in the name of airflow, horsepower, and the ever elusive gas mileage. Some companies like Volant have stuck to what I like to call a closed element design like the OEM or TRD designs, meaning the filter is completely closed enclosed in the airbox. Other companies like AirAid opted for what I like to call an open element design, meaning the filter is visible once you pop the hood, usually a CAI system like this would also have a splash/heat shield that is installed as well but it does not restrict airflow in any way really. It's common sense to think that because a "closed element" style CAI is drawing air from the fender just like OEM instead of drawing air from all over the engine bay like an "open element" CAI, that the "closed element" would be the better choice. (IMO neither are true CAI systems, a true CAI should draw air DIRECTLY from outside, not through the fender or around the headlights, aside from having the hood off a ram air hood or intake setup is actually the closest thing to having a true CAI) With all that said I'd like to point out that the filter style and design have a considerable effect on CAI "performance" IMO. Oiled filters tend to trap more particulate than dry filters but need to be cleaned and re-oiled more often than a dry filter would need replacing, oiled filters also tend to have a higher CFM..more air = more room for power. As for HP #s and gas mileage..ha, HP gains will be minimal at best and the problem with MPG gains is this, the stock intake is quiet, people usually don't notice intake noise with OEM, an aftermarket intake is usually drawing a lot more air and creating noise, people hear the noise and it sounds meaner and they think they can hear the extra power, short story they drive more aggressively because of the intake sound and any hope for extra MPGs goes out the window, that's my theory anyways. I'd also like to ask this, if a company makes a complete CAI system, and it included a throttle body spacer, would you use the TBS since it is part of the whole kit and generally to get the best performance you want to install all parts and supporting parts...opinions on this? As for me, I have an AirAid CAI using an oiled filter from AirAid, I have modified the shielding around the filter to clear the outlet for my hood which has ram air ducts, in my case I believe this is the best intake option since I have functional ram air, a "closed element" CAI would defeat the purpose since the airbox lid would block the airflow. I'm also running an AirAid prefilter because I have ram air, also makes maintenance intervals on my oiled filter a good bit longer, on avg I see 24+mpg around 45mph just cruising around and 20mpg on the highway around 65mph, any kind of aggressive driving results in the mid teens for mileage. What is everyone else running, how do you like it, and what are your opinions of what I stated above?