I've just sold my 2006 hse tdv6 done 78000 miles good car usual stuff went wrong nothing major,I've been looking at tdv8 sports done around 100000 miles would it be prudent to take the plunge and consider buying something with that mileage

Most important thing to check is service history, as I'm sure you already know from reading on here the TDV8's can suffer from turbo failure, personnely I change the oil and filter every 5k. If history is a bit iffy then walk away there are plenty of other cars about. 2008 G4 RRSport TDV8 current
2009 TDCi 90 current
2018 Discovery 5 HSE lux current
1994 Dakar current

Depends in the history, the paperwork, how clean the bodywork is etc etc. Would'nt put me off if it was a good well service and well looked after motor.

Not sure I'd move from TDV6 to TDV8 though. Maybe I'd go to the new SDV Engines. I'm not Fat. RRS TDV6 HST.

I would look for one with less mileage and put a warranty on it. 2014 L405 SDV8 RR Autobiography

2012 RRS SDV6 HSE -Orkney Grey with A/B bodykit - Now Gone
2007 RRS TDV6 HSE - Zermatt Silver - Gone

Think we proved service history doesn't count as any sort of guarantee for longevity or reliability. Mine only had 48000 miles on it and full history including major service 3 months before it lunched itself.
Beginning to realise a car that's used on a daily basis is more reliable than one which sits for weeks at a time.
My full fat seems ok but if I had to do it all again, I would save my pennies and buy an SDV6 rather than the V8. Just seem to be too many failures to be comfortable. 2x TDV6. SE and HSE. Both returned to sender with issues👀
TDV8 Sport HSE...... Gone. Loved it but it didn't love me!!
Now rolling in MY10 Fullfat TDV8 Vogue. Slammed it to go round corners🙈
Cruising daily #56 mph in a Volvo V8. 😱
Lots of other toys in the cupboard...😜