I've been using Mobil 1 fully syn turbo diesel for ( think that's 0W-40) for ooh, longer than I care to remember! Been used, er enthusiastically, but regularly changed and flushed 3/4 times a year on both 10 valve wagons. Never used a drop on either Alfa, and recently had tappets shimmed on one; mechanic said lack of wear was impressive for mileage ( nearly 150,000)and actually called me to ask wether I really wanted it done! I guess that speaks for itself. Is new life a rebranding thing?not come across that label before, but I expect any fully synthetic would give similar results. I'm sure you'll be ok with it.
Further to my previous post, have a look at oilmans' post entitled important oil questions answered ( sorry, still haven't worked out how to do links! ); that should reassure you ( it is beyond comprehensive; we are so lucky to have guys like this on the forum!), it is on the next page of posts at the moment. That will DEFINITELY help you!