Short runs in the winter kill the mpg. But long motorway runs in hot weather even with the air con on full, is right in its comfort zone as long as you resist the temptation to floor it. As Nodges says its a 2 ton brick.

Winter in UK about 24 mpg, Summer in Spain on motorways about 40 mpg. Possibly to do with cleaning the dpf?

Not a bad idea on any car

R4 I think

try this

intercooler

I agree very likely the pipe from the turbo to the ontercooler

Does the ignition come on? (ie the dash light up, steering unlock and immobiliser go off?)

If the steering lock has failed would it be cheaper to pick up a second hand steering column?

I have never tried it but is it possible to disconnect the steering column from the steering rack?

In winter or cold weather diesels burn extra fuel to keep the DPF clean so no supprise in the mpg.

Mamouth tape takes some beating but you have to get it clean and works best in the warm...

have a look at this. https://www.landyzone.co.uk/land-rover/total-electrical-power-loss.375978/#post-5283745

Try jiggling the steering as you put the fob into the dock. Often its too much for the servo to unlock the steering when it is pulling to one side. Until it unlocks the steering you wont get any further.

It should have had a major service last year so check the service record to make sure all the fluids were changed. (Did the previous owner get rid to avoid it). Check it was actually done not just stamped.

That’s exactly what I was about to suggest. The heat from the welder normally frees it off completely and it unscrews effortlessly. Make sure you don’t get weld splatter inside the engine though.

All turbos are in the process of failing from the moment they are made. Just how late do you leave it before changing it to be on the safe side? Sounds like they would have you change it as often as you can afford.

If a land rover stops leaking, check it has not run out of oil. Land Rover built a oil absorber into the sump guard which suggests they could not stop it. Is it getting through a lot of oil?

They may not have cleaned it thoroughly when it was manufactured and I would expect a certain amount of wear. If it sounds and works ok save your money. Worst case you have to replace it in the future.

Cheapest option see how it goes and do nothing as long as it’s all working.