It may seem like Exxon Mobil have cherry-picked the tests that were shown in this video because maybe they had a more favorable result than the competition, but rest assured they have done every possible relevant test on their oil and their competitors' oils. For the last 8 years they have had the largest R&D budget in the world, bigger than worldwide Shell, bigger than Chevron, bigger than BP, bigger than Sinopec and bigger than Total. They work directly with all major manufacturers and standards organisations to develop standards and approvals. They know how their products and their competitors' products work because they are so heavily involved in testing and analysing data. They are committed to making their shareholders shares more valuable, and their chosen way to do that is to make the best effort to produce quality products at all levels for competitive prices.
With regards to robertcope's comment above about how do the small blenders compete, it's in finding niches. If there weren't recipes for producing base oil blends for high-performance use, and additive suppliers Infineum, Oronite, and Lubrizol that supply pre-packaged additives for their exact needs, I can expect they would most likely be lost. This model relies on finding customers willing to pay 2X for proven supposedly Group 4 and 5 products that are showcased doing well in one specific area, like drag racing, motorcycle racing, road racing, light duty diesel trucks, etc., and by extrapolation can do well in your more mundane application.
