Modern diesels are pretty refined, not like the old donkeys of yesteryear. As Eric said fuel economy is way better and far outweighs any increase in cost at the pump. I drove the petrol grenadier to the south of France while I was waiting for my diesel to get the paperwork sorted. I have done over 2000 miles in the petrol. I like the diesel better. Unless you are driving it like you stole it you can’t really feel the extra hp of the petrol. The torque of the diesel is so much better, especially when towing. The petrol will kick down to 7th or even 6th gear where the diesel would still be in 8th. The diesel has a stronger gearbox too.
Some maths for you.
I have done 24000 miles in my diesel, average economy 24mpg thats 1000gallons, 4540 litres. Average diesel cost £1.50/l =£6810 spent in fuel.
24000 miles in the petrol. Average economy (and I’m being generous here) 20mpg, 1200 gallons, 5448l. Petrol cost £1.40 = £7627
In my experience the petrol actually returned 18-19mpg. And that wasn’t towing… The savings are pretty big and add up fast,