Originally Posted by BH_Fanaticos77
why would you think that? if you think about it, inline 6 is a long engine and can't really benefit from V-config packaging. It was shown that V8 in E92 is lighter than I6 in E46. I am not saying it will not be improvement in weight to E46 but it will not be necessarily lighter. Add turbos to that config and all that comes with it you can't be really serious about 100lb weight saving.
The S54 was an iron block while the S65 is an aluminum block. If the now I6 is an aluminum block, it could still weigh less than the S65, even with all of this stuff bolted to it. I don't think it will be noticeably lighter, but it likely won't be heavier.