[skyship007]

I should have listed the viscosity of Castrol Edge SLX Pro 5/30, which is 11.8 cSt at 100c, so the Mobil EP 5/30 is in fact thicker, which is good in my opinion.
In general terms if you check the oil finder page of a major engine oil company web site (I only regard Castrol, Mobil, Shell and Liqui Moly as major brands in the EU) for an engine specific recommended oil, it will be just as good as the Volvo dealers Castrol oil. I would not make the same statement about oil or fuel filters and think that using a real Volvo one is the best idea. The can might be similar to a German Mann oil filter, but the contents might not be.

I've looked at a lot of oil analysis results from various oil companies and the only general comment I would make is that Castrol do seem to make the best oils in terms of minimum wear rates, BUT Mobil and Shell both seem to make oils that clean better (More detergents and dispersant additives), which can be very important for older engines or long oil change intervals. Liqui Moly are half way between the two in additive terms.
Valvoline seem to make the best normal grade high mileage oil if you have a high oil consumption or leaks, as Maxlife 10/40 is one of the best HM oils around.

If you are desperate enough due to a terminal phase problem (Minor sludge, serious unrepairable oil leaks, gummed injectors or even Carbon deposits in the cylinders) to be in need of an oil or fuel additive, Liqui Moly are the best company in the snake oil game.

No oil company is making a special oil that will deal with the effects of diesel contamination. Valvoline do include some extra additives to deal with high Sulpur content petrol use, but nothing for diesel contamination. It seems to be just a case of moving up a grade or changing the oil more often. If anyone decides to try using Ceretec, it would be good if they would do a before and after used oil analysis and publish it here.