A8 engine displacement typo (?)

["Peter Grul" <pgrul.warm@Veda.com>]

Both on the Audi homepage and in the A8 brochure, the bore and stroke 
measurements listed for the 3.7l and 4.2l engines are the same:

bore   = 84.5mm
stroke = 93.0mm

Doing the math, the displacement comes out to 4172cc. Does anyone have the 
correct bore and stroke specs for the 3.7l engine? I assume the two engines 
are related, might they have the same bore, but different stroke? If this is 
the case, a stroke of 82.4mm would yield a displacement of 3697cc.

Peter
'93 90csq
North Wales, PA