No it doesn't.
I may have got a bit confused, as I was initially commenting on the fact that I wouldn't have been able to drive in major cities if I'd chosen a diesel car, and then I lost the plot completely!
I'm back on the medication now and can confirm that I was talking nonsense! Please...
And there was me getting grumpy because I wasn't offered a diesel option for my company car!
Though the mpg still makes it more expensive unless petrol gets considerably cheaper still.