They bench-tested the oils in a Toyota Prius/Prius Prime 2ZR-FXE engine (firing engine) to measure the fuel-economy improvement. They also dyno-tested the oils in a Nissan Rogue Sport MR20DD engine (motoring engine) running in a real vehicle. "SAE 0W-8 high-moly oil demonstrated 0.5% fuel economy improvement over SAE 0W-16 organic friction modifier (OFM) oil." How much of the improvement is coming from the SAE 8 and how much is coming from the high moly? It's obvious this is an apples to oranges comparison. We don't even know if SAE 0W-8 actually made the fuel economy worse by entering into the elastohydrodynamic-lubrication region in the bearings and increasing the boundary-lubrication friction in the cylinders and valvetrain. Obviously more transparency is needed, which is not being provided.