It is not much more efficient, which is probably OK - more useful to keep the price down than squeeze the last few mpg out of it. (greencarcongress.com)
Officially, the manual, front - drive car will do 64.2 mpg, which drops to 60.1 mpg with the DSG, a further few mpg in estate form and a further few still as a 4x4. (evo.co.uk)
It's also # 2500 more expensive than the diesel - powered 535d, while being heavier and doing fewer mpg. (evo.co.uk)