The fan is 2 speed but not much difference from low to high. Its a large blade and moves a lot of air. I have it on low speed and it cools easily. I think the high speed was only about 4 amps more draw. I had to trim the shroud with a die grinder and wheel to get the fit right on top and bottom but I'm really happy with it. Its almost a perfect fit to the core. My rad is just a stock unit. Temp drops quickly when fan turns on. Engine is only 9.5:1 though. Heres a link from when I installed it last season. Cleaned it up a bit since. Wiring etc. http://mmb.maverick.to/showthread.php?t=70707
