also, i have another question here. my car is auto, and usually when i'm doing 100km/hr on the freeway the revs should be around 2.5k when its warmed up and good to go. but recently, it seems to go back down a gear and i'm running around 3k revs when i'm doing 100km/hr. does anyone know why this is the case? do i need to change my transmission fluid? or is this the first signs of a failing transmission?