More impressive than the bald statistic was the Audi's ability to waft us all the way to Paris via Brussels on a single tank of fuel. Consider: 629 miles, 13 gallons. Name one other executive car capable of such parsimony. No, nor can we. Such a long motorway run was the perfect opportunity to savour the A4's blend of zest and refinement. While 110bhp may not sound too sparkling, a solid 173lb-ft of torque from just 1,900rpm means the 1.9 TDi can show many petrol V6s a clean pair of tailpipes at the traffic lights' grand prix.
On the motorway, that translates into terrific flexibility. Bury your foot in the carpet, even in a high gear, and the Audi surges towards the horizon as though connected by an invisible rubber band. Add in hushed refinement and a solidity of construction that inspires total confidence on the road, and the A4 stacks up as an ideal long distance companion. As a way of combining big car comfort with small car fuel bills it knows no equal.
Nevertheless, our holiday sprint did expose one chink in the Audi's armour. As a family car - which at almost ú23,000 it is - its appeal is diminished by a rather cramped cabin and limited luggage space. Camping gear and luggage for just two people proved a squeeze, leaving little room for rear seat passengers to travel in comfort. What's more, although the driver is cossetted by a fine driving position thanks to a steering wheel that adjusts for height and reach, tall drivers may find there's not enough room in the footwell to rest their legs comfortably. Mine kept catching on the centre console.
These reservations aside, the A4 has won over all who have driven it. As a way of combining executive prestige with supermini fuel bills, it's a magic option. Just remember that it's more style icon than load lugger.