lol good point.
But on the C63 side panels it says 6.3 litres when its not.
I ve not looked at my E55 for so long I've not a clue what it says no the side of it.
I recall reading something about EU legislation and rounding up when stating litre capacity rather than model number. Seems like it's a bit deliberately engineered at 6,208cc allowing them to say 6.3 litres. I'll try and look up the document but it's all a bit academic in percentage terms of overall capacity.
All the numbers and all, the best bit of the 6.3 is to know it's the only true AMG engine as all the rest and the new ones are Merc engines with add-ones!