Fan VS Fan

It's not the weight that sucks the power, it's how much they bite into the air. The amount of power a fan absorbs is proportional to the speed you try and turn it at.

The link you have is for a fan that is designed to move maximum air for a stationary engine. These engines operate over a very narrow rpm range and saving horsepower is not a major concern. I would venture a guess they may even be worse than a stock steel non clutch fan, certainly not something I would hang on the front of my car engine.