A side-load air filter cartridge comprising: a) a media pack for installation into an air cleaner housing via an open side of the housing , the media pack extending along a longitudinal axis between opposite inlet and outlet flow ends , the media pack defining an outer perimeter with opposite straight sides; b) a seal arrangement circumscribing the media pack outer perimeter , wherein a portion of the seal arrangement extends beyond a first plane defined by the media pack outlet flow end and a portion of the seal arrangement is disposed between the first plane and a second plane defined by the media pack inlet flow end ; wherein the seal arrangement is aligned along a third plane, the third plane being disposed at an oblique angle (A1) to the first and second planes; characterized in that the media pack is defining the outer perimeter with a curved end; c) a circumferential shell supporting the seal arrangement and surrounding at least a portion of the media pack outer perimeter , the circumferential shell including at least one engagement surface for receiving a closing force (F1) from a lock mechanism of an air filter assembly , the engagement surface being generally disposed orthogonally to the media pack outlet face ; and d) wherein the seal arrangement being disposed at the oblique angle (A1) to the engagement surface , wherein the closing force (F1) is directed orthogonally to the engagement surface such that a component of the closing force (F1) generates a component sealing force in the direction of the seal arrangement to form a seal against a sealing component of the air cleaner housing . a) a media pack for installation into an air cleaner housing via an open side of the housing , the media pack extending along a longitudinal axis between opposite inlet and outlet flow ends , the media pack defining an outer perimeter with opposite straight sides; b) a seal arrangement circumscribing the media pack outer perimeter , wherein a portion of the seal arrangement extends beyond a first plane defined by the media pack outlet flow end and a portion of the seal arrangement is disposed between the first plane and a second plane defined by the media pack inlet flow end ; wherein the seal arrangement is aligned along a third plane, the third plane being disposed at an oblique angle (A1) to the first and second planes; characterized in that the media pack is defining the outer perimeter with a curved end; c) a circumferential shell supporting the seal arrangement and surrounding at least a portion of the media pack outer perimeter , the circumferential shell including at least one engagement surface for receiving a closing force (F1) from a lock mechanism of an air filter assembly , the engagement surface being generally disposed orthogonally to the media pack outlet face ; and d) wherein the seal arrangement being disposed at the oblique angle (A1) to the engagement surface , wherein the closing force (F1) is directed orthogonally to the engagement surface such that a component of the closing force (F1) generates a component sealing force in the direction of the seal arrangement to form a seal against a sealing component of the air cleaner housing . <EOS>