>On average Diesel cars have higher CO2 emissions per kilometer. I don't think that's true (in the UK at least) - both in that it's vanishingly rare to find a

>On average Diesel cars have higher CO2 emissions per kilometer. I don't think that's true (in the UK at least) - both in that it's vanishingly rare to find a petrol vehicle that fit into the lowest 5 UK tax brackets (which are g/km of CO2) - and also in terms of real-world fuel use. I've owned probably 70 cars in the last 10 years or so (I buy and sell as a side gig), and all of the diesels have had lower fuel use for equivalent performance. They tend to be 'one size bigger' in terms of engine (so, say a 1.9 instead of a 1.6, or a 1.4 instead of a 1.1), but even taking that into account they will be a 10-20 mpg better on fuel, with a petrol 1.4 focus giving maybe 30 mpg average, and a diesel (1.6) one easily making 45-50 mpg, more on a run. And that means lower CO2 emissions. Yeah, you might see the occasional stupidly large diesel car/chelsea tractor, but most of them are 1.9D VAG, and 1.6 or 2.0 Peugeot/Citroen/Ford HDI/TDCIs - there are hundreds of thousands of them out there on the roads.