The 520d is punchy enough and it's our pick of the range. If you don't believe us, check out its claimed 0-62mph time of just 7.6 seconds, which is plenty for whisking you up to motorway speeds without any fuss. Performance is roughly on a par with the rival Mercedes E220d Estate's, although in terms of real-world drivability (as opposed to outright 0-62mph acceleration), the Audi A6 Avant 40 TDI has a slightly wider performance window making it fractionally more relaxing to drive. It's quieter than the 520d, too, although you won't be disappointed with the 520d's excellent mid-fifties average fuel economy and CO2 emissions, which drop it into a lower company car tax band than the Mercedes E220d.