My colleague shows just the opposite with his 4-ball testing. Mobil 0W-40 has organomoly additive for enhanced boundary lubrication and works better than Mobil 5W-40 where boundary lubrication is an issue. The 5W-40 grade doesn't have organomoly additive. In fact, the Mobil 0W-40 held up better than many other oils in 4-ball testing. 4-ball testing is very similar to the test presented in your link.

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95 E320 Cabriolet, 169K