Well guys, curiosity got the better of me. I fell for this whole snake oil phenomenon of these throttle body spacers. (I have a great tool for evaluating mileage; my truck has the fuel computer/nav stuff. I can reset it, hold steady speeds over the same roads and watch the ‘instantaneous mpg’ readout while driving.) I purchased the Auto Extreme TBS, installed and enjoyed it (yes, I cut the screen from the o-ring). I did notice greater response in the 0-1/4 throttle range and an increase in mileage. In an effort to get more of the good stuff I then bypassed the throttle body coolant and modified the snorkel inside the stock air box; both of which I consider worth doing especially considering the cost. They seem to help a little bit, perhaps the same amount as the Auto Extreme TBS. My net gains seemed to be in the neighborhood of ½-1 mpg around town. Perhaps even 1 ½ mpg better on a run.
I shared this with an Armada owning buddy of mine and he drove my truck and agreed, it feels more responsive (we both have the 3.36 axle). He asked me to collect an Active Tuning Ground kit and TBS for him. It was at this juncture I decided I had an opportunity to try an Airaid TBS and he could wait a little while I test drove the Airaid on my truck. That was the price he was going to pay for free labor.
I now have some time on the Airaid. No dynos involved but I believe it works a little better. MPG is up another ½ to 1 in all types of driving. The 0-1/4 throttle is still good, I can’t claim better than the Auto Extreme but certainly not worse. I will tell you the whistle with the Airaid is no less than obnoxious! Remember the old Nissan ads about dogs loving trucks? They don’t like this one anymore
…
Having said that, for me, the damn things work. The Airaid works better, whistles and costs more. He’ll never tolerate the whistle so I think I’m going to be stuck with it
.
Hope this is of interest.