Update: I did think that the 63 was part of the name. I was wrong. In my defense, not having done any research up till now, the SLS is/was the ONLY MB or AMG class not to have displacement #s as part of its name. I wrongly assumed that since every other MB that I was familiar with had these #s, so too did the SLS. This morning I also spoke with a salesman at Euro Motors about this numbers/name thing and asked him this ? several ways to be sure. He said NO 63 in SLS. Interestingly, the SLS successor, the AMG-GT, also has no #S in it's name. I guess you're supposed to know the displacement of these peak performers. Interestingly enough, again, speaking of displacements, on the Wiki MB page, I located 2 different displacements: 6.2 (+ a small fraction) & 6.3. Why round 1 up and not the other? For some one else's scholarship. It's impossible (with one exception) to find MB SLS 63 AMG all together. The exception being: Google Mercedes Benz SLS 63 AMG; Images; you'll find 2 plus pages of photos, 43 images of this car, labeled thusly. Enough? OK? OK.