K&N drop in air filter

[jeep1350]

Do K&N dorp in air filter let dirty into engien or are they good at keeping dirt out of engien?

 

[tjkj2002]

Do K&N dorp in air filter let dirty into engien or are they good at keeping dirt other stuff out of engien?

Any oiled air filter will allow bigger particals past since they where originally made for race car engines that do not need to last but maybe 500miles at most but needed less intake restriction.Stick with a paper filter.