Matsayin farantin kariya na ƙasa na sandar gaban motar: 1, don hana ƙananan abubuwa yin fantsama cikin injin injin yayin tuƙi, haifar da lahani ga injin, ko taɓa kwanon man injin lokacin jan ƙasa, yana shafar aikin injin ɗin na yau da kullun, tare da kiyaye injin injin; 2, a yayin da ake yin yawo, yana iya hana ruwa fantsama cikin injin injin, da kuma hana sashin wutar lantarki jika da ruwa da haifar da matsala.