I'm not sure about the single , but the dual bypass filters down to 2 micron , so it need s to let most of the oil bypass becouse of the restriction , and the oil fets clean by passing through the filter multble times , if your famiaier with how black used diesel oil gets and then put in one of these after about 1/2 hr of runing the oil looks like new , and thats good enough for me to have on my truck.