I bought it for its underdriving abilities to reduce the parasitic load of the water pump and power steering pump. Weight loss was less than a pound - insignificant. It was just the most expensive part of an ongoing fuel economy experiment that began on July 23, 2007. My focus on this experiment intensified in May, 2009 when I found ecomodder.com. I knew that in a worst-case scenario, the underdrive pulley would not
decrease my fuel economy. It gave me a significant increase - more than anticipated.
I didn't buy this pulley for more power - this 4-liter V-6 at 210 HP has plenty of power. I can accelerate to the speed limit on all but the shortest freeway on-ramps without exceeding 2500 RPM. Cruising, I'm always under 2000 RPM. If I'm going less than 50 MPH, my cruise RPM is between 1000 and 1500 RPM. (depending on speed and gear)