td5 how many miles are they good for?

Hi
I have a 200tdi with 135k on it still as strong as an ox.
I am going to look at a td5 90 at the weekend on a 51 plate it has 100k on it been serviced every year from new by the same landy specialist, i know next to nothing about the td5 are they good for the miles like the tdi?
couple of mates have said they are a weak engine but neither has ever run one so what is the truth,they cant be that bad can they?

My Disco is on 175k, serviced right there is no reason why it would be any worse than any other engine really.

185K here on a 04 plate fender, the last 120K have been towing 3.5T everyday, recentl had the gearbox reconed as 5th gear was whining a little, only things to look out for are diesel regulators and oil in the loom

2000 110 TD5 195000 - new head and lots of bits and pieces along the way, but part of the family and owes nothing at that mileage really. Could do with a few less leaks, but its done that since it was new...!! A