Genuine 1.9 PD mpg figures

[dubber36]

A mate has a 2003 V6TDI that he's had from new. It's only done about 60k, but now his mileage is likely to rise, he thinks it's going to cost too much to run and is thinking about trading it for a 1.9.

Now I'm a firm believer in better the devil you know and have tried telling him that buying a used car with unknown history could be a complete minefield. Even an unseen £200 job that needs doing on another car would pay for a fair bit of extra diesel needed to fuel the V6.

I need to back my argument up with numbers, so what genuine brim to brim mpg figures are you 1.9PD drivers getting doing mixed driving? I don't want to know how many miles you get from £20, or beer talk 80mpg on a long run, just an overall average doing normal day to day stuff. I don't think when I put the actual money into the equation, it's not worth making the change.