So I've done three VRP oil changes on a K 24 Honda with 200,000 miles.
Over about 12,000 miles, an increase in fuel economy of about 5%. Nothing else changed on the vehicle, not the driver, not the tires, not the places traveled.
Prior to VRP, oil consumption was around 1 quart per 1200 miles. It has stabilized at a half quart every 1200 miles.
The reduction in oil consumption happened after the first oil change interval. It has not decreased or increased since. I typically don't top it off with VRP because I need a full five qt jug for an oil change so I just throw whatever random crap I have in the cabinet in there. It might be 10w30, it might be 5W 30 maybe 0W 20. I don't really care. I don't invest a lot into this vehicle when I'm topping it off with the oil, just making sure it doesn't run out. So unfortunately by the end of the oil change it's about 60% VRP and 40% random top up oil left in the engine.
I think this is the end of the line for the VRP. I have some of the Valvoline 150,000 mile oil sitting in the cabinet I'll use next and compare the outcomes for 3 OCI to see differences over the next 18 months.