If you’re planning to use the van as a camper for rural trips then the new diesel rules won’t really affect you. The new rules are designed to limit the numbers of older, more polluting diesels entering major towns and cities: vans.honestjohn.co.uk/features/what-is-the-ultra-l.../

Diesels still have an important part to play for camper van drivers, because a petrol engine would cost a fortune to fuel over long distances. However, I’d aim to buy something newer for a camper conversion, like the Transit Custom diesel, as the old Transit has quite a poor reputation for passing the MoT: vans.honestjohn.co.uk/mot/ford/transit