"Officially" Mercedes has stated the 2010 S63 (6.2L V8) will produce 518 HP, while the uberexpensive S65 (6.0L V12TT) will push 604 HP.
now my question is why make a 5.5L V8TT as well as offer the above engines??? if htey plan on replacing the 6.2 V8 with the 5.5 i think they SHOULD change the name,.. but i think many AMG buyers will not want to associate their high(er) end cars with the lowly (supercharged) 5.4L V8 from the W211 and W220.
do note that MB had alot of history with the 6.3L in the 300SEL (hence the modern 63s) so it is possible the new 5.5L V8TT uses the legendary "560" badge... it's not like i know what i'm talking about,... i'm just saying 