Diesel, litre for litre, contains 10% more carbon than petrol. But the engines use about 60% of the fuel a petrol does, so Diesels come out on top overall, as well as lasting longer (more carbon efficient) and being more reliable.
We hammered a 1.6l Citroen P4 Picasso around Europe last year (150kph on the motorways), five of us plus luggage, and averaged 5.8l/100km. That was a brand new engine. When it's run in it'll be a lot better. Hypermiling would get you around 3l/100km. What do we get here? Falcons and Commodores. My Patrol is far more economical than them!!
The govt. really cares about CO2, eh? So much that it has banned imports of that Citroen into Australia.
