FWIW, my new V70 D3 is a 5-pot Volvo engine, 2.0lt and also £30 tax.
Around town it is not as efficient as the old Galaxy that had Ford/PSA 2.0tdci, Galaxy perhaps got 30-35, Volvo maybe 30. Long runs the Volvo is far better – 45-50 (indicated as 53+), Galaxy only 40 tops (indicated as 55…!).
I have bought it as I do 20-25k a year, with at least two long journeys a week. For this it works, and makes economic sense and if I can run it as long as possible, reduces environmental cost. The long runs will keep it cleaned out and working well.
I have little petrol Seat Ibiza estate for local / town / cities etc Again I bought that based on maintenance cost, so simplest engine I possibly could. Again, part of this is maintenance cost on it for local journeys – no turbo, clutch is £75 not £500 DMF, no EGR etc etc.The tax is £140, but so what when I am three years in an done nothing but tyres and service? I bet if we had used a modern diesel in that time we would have had bills, and possibly big bills for EGR and DPF.