[HDi fun]

Diesel is probably still cheaper to run in pence per mile terms for fuel only. And only if you compare similar performing cars. You can't compare by engine size anymore as a typical 2.0 litre modern diesel will destroy a 2 litre petrol equivalent in terms of performance.

Dial in diesel engines' higher servicing costs and the higher purchase price of diesel cars and the diesel will lose the pence per mile shootout