MPG for my new A4 SE Technik (163)

Hello all. Well, I picked up my new car yesterday,and I have to say it's absolutely stunning, both in looks, and to drive. The only disappointment immediatley is the MPG. I did a 20 mile trip to work this morning and drove VERY sensibly, aircon off and not over revving. The majority of the journey was on dual carridgeway and motorway, and when I got to work, it stated that I'd averaged 51.2 MGP. Now, while that's very good compared to my old car, it's nowhere near the stated MPG from Audi. Is there a magic setting on the car somewhere, or should I only expect to hit near 60 on a constant motorway cruise for a couple of hours?

Any input welcome

BTW, picture attached. It was the colour that swayed me :-)