In message >
(TK) wrote:

> Is the only difference the larger engine ...

The A6 has a larger range of engines. The allroad is only available
with 2.5TDi, 2.7T and 4.2 V8. The A6 is available with a variety of
powerplants 1.8T - 4.2T (RS6), and 1.9TDi - 2.5TDi.

--
Peter Bell (Note Spamtrap - To reply, replace 'invalid' with 'bellfamily')