For the money of what these run, its cheaper to run a better fan/shroud set up with a 180* T-stat that will achieve even better results.
Switched out my '97 fan set up with one from a 2002, that made all the difference in the world right there. Then, changed the settings for the fan in the computer, wha-la. It only cost me $25.00 and time.
Rule of thumb there...just because they (anybody) sells it, and has claims of gains, doesn't mean you should buy it. Surprised the vendors are not selling electric superchargers...I mean, they give you 500WHP with a simple bolt on mod, what could be better! Ebay sells them, so they must be good. lol
~F~