Ok, please excuse ignorance but when the diesel vs petrol issue comes up the first recourse is to the expected mileage. I do 20-22k per year and yes I would expect to be pointed to a diesel because as I see it the higher price is offset by the mpg. BUT, if the cost of fuel were taken out of the equation are there other reasons why you would go for diesel with a high mileage (I intend to keep the car for 8-10 years so expect to notch up 160-200k)? Durability? Lower maintenance costs? Anything else?