The benefits of Electric vehicles in the city, are really outweighed by the high levels of CO2 they are responsible for, so we cannot recommend their use in any context until the generation of the UK's electricity is cleaner.
Just like Electric vehicles, LPG vehicles are also great for the city. But just like Electric vehicles they also have a significant impact on CO2 levels, and we therefore cannot recommend these either.
But the two biggest surprises are with Petrol and Diesel vehicles. Petrol vehicles are the highest contributor to CO2 levels, so it is odd that some people are switching to them from Diesel vehicles. We can only assume this is because of mis-information in the media. Diesel vehicles actually produce very low CO2 levels, and it seems odd they are not been openly praised for it. Further still, if you live in a remote area or a small village, the negative effects of Diesel or Petrol cars, to the immediate area are not even worth considering.
So unless you live in a densely populated city, the best choice is probably a either a Diesel or Hybrid, whichever suits your needs. However if you do live somewhere densely populated, the only sensible choice is a Hybrid vehicle.
What is interesting, is that Diesels are not so bad after all, and the high levels of taxation they attract, are clearly, grossly unfair. LPG owners are actually polluting far more than we realise, and are getting a lucky tax break they perhaps do not completely deserve. But the biggest revelation is that Electric vehicles are still not the "knight in shining armour" they are supposed to be, and it is incredibly unfair that they are offered so many incentives and tax breaks, when they are not actually the best solution for our planet, and our health.
I hope in time, our governments realise, that they should really be promoting Hybrids. Perhaps it's time we started seeing LPG-Petrol Hybrid vehicles?