Originally Posted By: zveroboy
Well, after 3 OCIs with SHU GTL 5w40, I'm amazed by it's longevity: it starts feeling tired ( changing sound/smoothness) at ~ 11-12 000 km !!
It's way much stronger than the other oils I've used ( 6-8000km)
Yep, I agree, Shell Ultra 5w40 is a real star. The only oil I've tried in my TDI that produced similar UOA results was the more expensive Liqui Moly Synthoil High Tech 5w40 (Both Acea A3/B4). The best ring cleanliness and min friction results were based on the 0w40, but I doubt if there is any difference in the additives apart from slightly less VI (Viscosity Improvers) with the 5w40, so the results might even be a tad better with that version of Dutch liquid Gold.
I buy my engine oils online and 5 liters cost me 29 Euros inc postage in Germany (I spend half my time there), which is far cheaper than M1 or Casteroil Edge.
I can only use an 0w30 in winter, as there is a temp limit of 30c for my engine for non Xw40 oils.