[Phantom]

I would figure that drag would be about the same as a sold grill block or slightly less. The reason is that at high speed the air that gets stopped creates a stagnation point forcing air away from the grill, by doing this less air entered the engine bay reducing the drag created by the turbulence in the engine bay. So the real question is, "Does the small increase in surface area and drag created by the screen decrease the drag created in the engine bay more/less/or by the same amounts?"