Instruct: Classify Amazon reviews into positive or negative sentiment
Query: More airflow = less filtering

After I received 2 filters for my 2 cars, I was alarmed by visible less filtration fiber in K&N; filters. In many instances you can see small openings in the fiber.Fiber has some oil that helps to collect dirt from air, but sometimes that can also mess up ignition things. Filter build solidly, but the main working function clearly not as good as a regular ( original) filter. I went on other web sites to read reviews about it. Many people impressed by it's solid build, but informed ones all point to potential problems from using it. Bottom line it will allow more air, but at expense of allowing more dirt in to an engine. Following common sense, in industrial settings nobody uses type of filters as K&N; does, in semiconductors manufacturing, in clean rooms all filters are HEPA, and fiber type similar to regular (original) filters. Using K&N; filters might void warranty on your car.Will be returning these today, and will get original ones at third of the price.