Diesel cars are far more economical than petrol cars and the majority of Audi, VW, BMW and Mercs here are diesel. All the jap cars such as Mazda, Honda, Toyota etc are petrol. Petrol is far more expensive here as opposed to diesel and they regulate the horsepower of cars here by an increase in motor tax example: the greater the hp, the higher the tax.
I owned a multitude of jap cars at various stages and they fucking DRANK petrol spending on average of 50 bucks a week on fuel just to do a daily round trip of 20 miles to work, taking into account that I was driving an "eco-friendly" 1.5 litre engine. With diesel, I get 2-3 weeks on the same quota. Sure jap cars are built like tanks engine-wise and give little or no engine trouble compared to Fiat, Ford, Renault etc but they are costly bastards to run.