This is far from scientific, but I'll share this:
Up until January of this year I had a 2020 Jeep Grand Cherokee with the 3.6L Pentastar V6. It had a steady diet of dealership oil changes every 5-6k miles throughout its entire life. From what I've been told on this forum, that dealership 0W20 is actually Pennzoil Ultra Platinum oil. Judging from the inside of the throttle body, underside of the oil fill cap, and heavy varnish on the dipstick the engine was pretty dirty.
I ran Valvoline R&P in it beginning at 200k miles on the odometer. Within a week I was already seeing the varnish on the dipstick disappear. There were signs that the Valvoline was doing what it claimed to do.
So that raises the question... if the Valvoline R&P was reversing the crud left behind with PUP, can the two oils even be compared? To me it seems like the R&P really is something different. If other oils were just as good, the Valvoline wouldn't have had anything to clean up to begin with.
Up until January of this year I had a 2020 Jeep Grand Cherokee with the 3.6L Pentastar V6. It had a steady diet of dealership oil changes every 5-6k miles throughout its entire life. From what I've been told on this forum, that dealership 0W20 is actually Pennzoil Ultra Platinum oil. Judging from the inside of the throttle body, underside of the oil fill cap, and heavy varnish on the dipstick the engine was pretty dirty.
I ran Valvoline R&P in it beginning at 200k miles on the odometer. Within a week I was already seeing the varnish on the dipstick disappear. There were signs that the Valvoline was doing what it claimed to do.
So that raises the question... if the Valvoline R&P was reversing the crud left behind with PUP, can the two oils even be compared? To me it seems like the R&P really is something different. If other oils were just as good, the Valvoline wouldn't have had anything to clean up to begin with.