Was messin' 'round with the truck this afternoon and had some extra air in the compressor so while I had the hood up I thought I'd see how much air would come through the bug screen. I was kinda shocked when I placed my hand behind the screen and grill and felt very little air coming through! These screens seem to be effective at keeping bugs out of the front of the radiator but may not be good for keeping the engine running cooler and allowing adequate air flow. This was by no means a scientific test but would like to hear from others with more knowledge on this.