Would a day’s training give you the confidence to tow a caravan through London?

There’s little wonder that caravanners - along with horse box, boat and trailer users - cheered when Mazda took the unusual decision to launch a new diesel engine in their flagship CX-60 model this year.

And not just any engine but a 3.3-litre in-line six-cylinder unit, which they claim must work less hard than a smaller unit, and is therefore more efficient.