With all of the talk about 0w20 vs 5w30, I found this particular study very interesting. I recently came across Ravenol DXG 5w30 for my Enclave V6 GDI engine, (which looks very interesting with Group V PAO, 6.0 Noack, and 256°C flash point.) Admittedly I'm a little on the fence with the 0w20 that GM calls for their V8 trucks, especially when in the instance of my 6.2L V8 L86 calling for 0w20, which is essentially same long block used in the C7 Corvette (LT1) which until recently, has called for 5w30 for years but is now saying that 0w40 is what you need to use going forward. Needless to say, I'm interested in Ravenol and trying to get their 0w20 DFE with DEXOS1 Gen2 rating over here in the US (for all the GM trucks!)
In this study, they used an identical fleet of six 2015 Toyota Aygo commercial vehicles (1.0L engines) used for in-home nursing services, Ravenol ran half the cars with their new Ravenol EFE 0w16 and the other half with ACEA C3 5w30 oil. The drivers all changed vehicles and never knew which one was which. They ran 5,000km OCI's.
The Ravenol 0w16 viscosity remained virtually unchanged over this period and retained its TBN much greater than the 5w30. With an average decrease in fuel consumption of about half a liter per 100km, meaning that essentially the vehicles could drive about 53km more on a single tank of fuel. Long story short is, apparently, the 0w16 provided better wear and fuel mileage than the 5w30. Ravenol EFE 0w16 vs 5w30