Every thing that I have been able to find says that these thinkgs DO NOT work on our trucks maybe some small improvement on carb vehicles but I doubt it if it was so great ppl would be yelling about it on here what with everyone looking for better gas mileage
Think about it.
Stick anything passive in the airstream and guess what will happen. Fuel injection will compensate for intake air flow changes anyway. Carb system would result in running a little richer perhaps but that sure as hell ain't gonna give you BETTER mileage.
Have yet to see any LEGITIMATE dyno tests. And I doubt I ever will.
With all the misinformation I am surprised there hasn't been some legal action - maybe there has ? For example - Horsepower gains UP TO XXX - that includes ZERO.
If it sounds too good to be true - it probably is.