With its revised engine and gear ratios, and low rolling resistance Michelin Primacy HP 205/55 R16 tires, Audi claims the A3 1.9 TDIe is good for 53mpg on the highway. In more than 500 miles of fast freeway hustling, rush-hour grind and regular urban running last week, my tester averaged 44.3mpg without any econo-driving techniques. (All the mileage figures quoted here are for small-sized US gallons, not the generously proportioned British ones.)
On a 48.5mile run to London's Heathrow Airport around the jammed M25, one of Europe's busiest freeways, I averaged an impressive 50.5mpg in the sort of bumper-to-bumper stop-start traffic you find on the 405 here in LA every day. Flicking through the A3's trip computer at the end of my drive, I found the car had averaged 42.6mpg over the last 1454miles at an average speed of 51.2mph. By contrast, our long term Prius never managed better than 47mpg between refills, and averaged 41.6mpg over 22,278 miles, most of which were on LA freeways.