I absolutely love my 135i but let me tell yeah the dealership gave me a loaner n55....and man that car is pretty damn fun. But like the other posters up here say, you cant go wrong either way. One is just more reliable than the other. If it were me and i had a few extra grand, i would go with the n55. Not dissing the n54 at all but im basing it off of reliability. Because, honestly, who is planning on doing a single turbo upgrade here?
Cars: SGM 325i (Retired) l BSM 135i (Retired) l SS to Gloss White S2000 (Retired) l Arctic White RS4 (Retired) l White GTi (retired) l AW 335d M-Sport