Hi chaps bit of advise please looking at a A4 or A6 Avant was wondering how much larger load space passenger space is in the 6 over the 4 what would be the best engine for balance between power to compete on the open road and economy in both cars.

Been told the 110 bhp td is great in the 4 but is it enough in the heavier 6.

Changing from a 320 auto e36 which is great on the motorway but sluggish in town with the saxo brigade trying to race.

Many thanks

Have about 3k to spend so any guidance of age condition etc I might get for that would be helpful too.