Z6 is the engine i currently have in my car and its well worth it, i gave that bad boy at least 20 trips to jax back and forth and 2 oil changes in between and it still starts like the first day... reliable 30mpg+ all day!!!! if i wasnt into performance it wold be the engine that for ever would stay in my car but you know that when you are into HP you need to go big so mine is leaving but great experience that i had with my z6...