How much does the new astra 1.7(110hp) average mpg?

[DaveWilliams]

I want to know the averange mpg i will have out odf the new vauxhall astra diesel, I am not heavy on the throttle but im not light at the throttle im a bit over a average driver speed so what will be the average mpg i would be doing on the astra and what would the average be if the car was a 1.6 petrol also?