Really modern diesels need to do long journeys, they don't like short stop starts, it clogs everything up and when they go wrong they do cost considerably more than a petrol, amd most garages still struggle to diagnose issues correctly, and tend to just Chuck parts at them until the fault is fixed, and more often than not the problem ends up getting masked as being fixed only to come back in a couple of weeks.
Our Mondeo pool car at work had best part of 4k spent on it year before last over the course of a year.
It was smoking heavily upon acceleration and going into limp mode. At the start we said it was the injectors needed replacing and the dog cleaned as a result.
Well the diesel specialist didn't want to trust our judgement and started out saying it was the 5th injector clogged up, replaced that for £600, a week later, oh the dog is blocked again and it won't regen, need a new dpf. Fit that for £600, a week later, the aftermarket dpf fitted isn't any good we advise to get a genuine one that's the problem, another 1200 quid (parts only).
2 weeks later, limp mode again, dog needs a regen oh and we think the turbo is faulty. Another 700.
Throughout ball this we kept saying are you sure it's not the injectors? Kept getting told we've checked them and they are fine.
Another couple of weeks go buy, dpf blocked again, oh it's the egr valve causing bit to coke up. So we decide to get it deleted and mapped out. Another 500
4 weeks later dpf blocks again, now we told them outright change the bloody injectors like we asked you at the start. 800
Problem solved. Luckily we are on account so we withheld payment until they agreed a considerable discount on all work carried out beforehand for their lack of diagnostic ability.
If the car is PCP or such like and you plan on replacing bit every couple of years then diesel is fine as everything is covered under warranty really, if buying outright I wouldn't bother, especially as petrols these days are so good on mph and power ratio.
That said the 6 cylinder diesels found in the prestige German cars are gorgeous, sound nice and Christ they are powerful. But they are like a private yacht will make you bankrupt given half a chance