Why do you want a diesel when you only do 5k a year?

We drive down to Cardiff a few times a year, last trip in a 2010 Vauxhall hire car, the petrol was 80 quid annd it's only going to get worse. Diesel should be half that.

Most modern cars will do starship mileage if correctly service but Iwould reitterate the above post 5k a year it will be far cheaper to run a petrol.

I just did a quick calc using Parker's guide Petrol vs. Diesel comparison. I did it for the Passat CC as the other Passats in the list were too new. So, for an 08 plate Passat you're looking (Autotrader price) at about £12k for the petrol and £14k for a diesel one. Petrol at 135.9p/l costs about £900 per year. Diesel is comparably at 140.9p/l so that about £940 per year. This is rough so bear with me! Parker's calc reckons that it'll take you 38k miles to break even. I don't know if I like this calculation; I think it's a bit high on their part but it'll still leave you slightly better off having a petrol than a diesel. Obviously this will depend on your driving style too.

I think the threshold mileage for buying a diesel is currently about 15k.

The VAG 2.0 diesel is a great combo of performance and economy but has suffered from problems (some catastrophic).

The diesels command a higher used price and you may get an equivalent, but lower mileage, 2L petrol for less and it would suit your usage better imo. Worth a look, everyone seems obsessed with diesels nowadays, myself included!