Why are you assuming that an aftermarket intake will allow more flow then the engine can consume than the stock piece? Do you think, that as Toyota, they would restrict their motors performance by placing an undersize filter element in it? NO. The filter size and flow are MORE than enough from the factory, as I have demonstrated. Where the increases come from are in the removal of the noise reducers and less turbulent path.
And, if you'd like to get down to it, hot air will provide you with the best mileage.
Cold air - power
hot air - efficiency
It works in the same manner as a 40 degree ice tray freezing faster than a 100 degree ice tray, all other things equal. It just take less energy to make the matter conversion.
Hot air will more easily combust than cold air....but cold air packs a denser air molecule for the same volume of flow.
Guys, I'm not trying to pull your chains or anything, I'm just stating the facts. Like, I said, the only thing that is of benefit to your engine is the smoother path. The stock box performs as it should and the stock filter and even the diameter of the intake path has been oversized from the factory. Even though I havent done the calculations, I can almost guarantee it.
You tell me how putting any different filter on it will help with flow if it's already getting every teeny weeny bit it needs to produce its max power?
Besides, your valuations of your mpg increases are anything but scientific.
Here, look at K&N's explanantion if you dont believe me.
K&N Frequently Asked Questions (FAQ)
Do you know why they dont advertise increased mileage?? Because they cant....it simply isnt provably true.
I'm not trying to upset any member or anything, I was just sharing my experience and knowledge on the matter because engineering quality performance intakes is what I do as a business.