Got around to testing for some real numbers. Unfortunately it is only for fuel economy.
Here is the intake mod I am talking about
Here is a comparison of the mod with the stock setup.
This first graph is RPM vs the MAF sensor reading. Considering that there
IS a difference I would not worry about a lean condition resulting from the computer not knowing that there is more air coming in than usual as seen in aftermarket CAIs. The pictures are a visual representation of datalog readings. When, for example, the RPM was
AT 2500 rpm and the MAF was reading
AT 70 g/s, a dot was placed. With enough similar readings the dots begin to overlap and show trends.
The scale is a bit misleading (and made worse by compression for internet use) but at 2500 rpm there is about 3 extra g/s (grams of air per second...and since air weighs next to nothing that is a difference) and about 10 extra g/s at 5000 rpm.
Since I didn't have a dyno to test the before and after I can't say how much of a power increase the added volume can add.
But that graph says nothing about fuel economy right? Well that leads to the next graph.
This graph is a little backward because the axes are flipped(blame MS excel) but the results are still the same. This compares the MAF sensor reading and fuel economy (IECON).
Anyone looking at this will see that it promises 3 or 4 mpg...well not necissarily. The peak efficiency (Most mpg from a given amount of air) is under
the best conditions. Obviously anything below optimal will be below that curve. The peak conditions are usually flat smooth roads with little turning and for shorter sections that are down hill. Sometimes I was barely putting any pressure and that is how the 25 + showed up (or at least that is the only way I can think to explain it). I would consider anything below 23 mpg for this to be reliable because I can get up to 22 mpg on certain roads. 18 mpg is almost always expected for cruising, 19-20 is common for many roads and then there are a few roads where I get 21-22 every time
Edit: I want to mention that the high mileage was with the intake mod installed...there is no way my truck will get 27 mpg in the current state it is in.