It depends what you call drive like a nun, my driving like a nun (occasional right foot) I get 28mpg. If I drive normally I get 26mpg, if I use the car like its meant to be driven 19mpg. Are you used to a turbo car? Because sometimes it takes a little getting used to, to realise how to optimise the mpg. Like where the max torque is so to not use the right foot as long as you need to.