Diesel is still the fuel of choice when you look at actual emissions on the new test regime, compare 540i to 530d in the G30 Feb 2017 drip down:
We are being talked out of diesel by the press, but a good diesel will produce less particulates than the equivalent petrol engine, purely because diesel has been developed more than petrol in the last few years. It would be a shame to lose all that development and testing just because I’ll informed ministers and the tabloids don’t like diesel.
Read Autocar and they tell you that there is still nothing like a big diesel in a Range Rover or an X5 where hybrids simply do not work.
Do your homework before deciding petrol is best as I don’t think diesel is dead yet.