[tl:gallery size=460]

Car manufacturers are very proud when they save weight from their new models. All other factors being equal, a lighter car will deliver better economy and lower emissions. That means cheaper fuel bills, lower Vehicle Excise Duty, and smaller tax bills for company car drivers.


Take the new Audi A6 Avant. Audi is very proud that this big estate car has a kerbweight as low as 1640kg for the 2.0-litre TDI model. Along with the efficient engine and a range of clever technologies, that low weight contributes to official combined fuel economy of 57.6mpg.


Just about the only motorists who won’t welcome the A6 Avant’s lightweight wholeheartedly are towcar drivers. If you have a heavy tourer to pull the A6 is at a disadvantage compared with the BMW 520d Touring, which weighs 1785kg, or the Mercedes-Benz E220 CDi Estate, which weighs 1845kg. Compared to the big Merc, the Audi’s 85% match figure of 1394kg is 174kg lower. That’s a significant difference when so many tourers weigh around the 1500kg mark.


Aside from this reservation, the A6 Avant should make a fine towcar. The 175bhp 2.0-litre engine has plenty of punch, and the firm ride bodes well for stability when towing. The more powerful (and heavier) four-wheel-drive models add greater performance and all-weather traction to the 2.0-litre’s virtues.


The interior is well made and spacious and there’s 565 litres of luggage space with the rear seats upright, rising to 1680 litres once they’ve been folded.


The A6 Avant is one of the best big estate cars so long as your tourer is light enough to make a suitable match.