Hi all, I just was talking to a mate of mine that is quite deep in with an oil company here in Aust. He pointed out a interesting point to me about Syn and Min oils, that I thought I would see what you guy's all thought. Now keep in mind were talking about the two in the same vis, just to keep it far. mineral vs synthetic. It's really hard to make generalisations about product quality if we're just talking mineral vs synthetic. For example, (and both of these examples do exist) It is possible to go out and make a fairly borderline quality oil, throw in 5 or 10% of a synthetic base oil and call it Semi-Synthetic and pretend that it is something special that out performance Mineral's. It is also possible to spend a lot of time and effort making a really good mineral oil that is much better than the oil above. mineral oils are not mineral oils. There is the basic mineral oil that has been around for 100 years. Then there are more highly refined versions that are relatively new technology that are much much better than the traditional mineral base oil. Using these oils as a base, you can do much more with the product than when you use the 'old style' oil as a base - you have a much better starting point. SO what I'm wondering: I guess what you could say is that for eg only, that Valvoline's Dura Blend 15w 50 as a semi Syn could not be as good as say BP's Visco 3000 15w 50 as a Quality Mineral? And from the consumer point of view there is no real way of being able to tell if borderline quality oil, has just had 5 or 10% of a synthetic base oil and the company call it Semi-Synthetic and tell you it' there top product is there. Also to add does anyone know what Group Dura Blend is classed as?