The "independent" tests show exactly predictable results - better "cleaning" - less air gets through. Look at the first graph, and at the last - same filters, same order. Better filter filters a dust - less air is getting through. As we discussed, to get better performance, you have to get more air. So, with "cleanest" filter your engine will get very clean air, but it will "starve for air". In opposite, if you get "high performance filter", you will get more air by sacrificing an air quality.