I'm seeing some positive results on my nissan oil burner after a kreen piston soak as well as 3 kreen runs in the oil. The last time I added a pint and drove it for 1k and then drained and refilled with maxlife 0-20 which isn't the correct viscosity, although it's called for in the same engine from 2013 on. I have a new, low mileage yard engine that I'm going through when I have time so I'm not really concerned about my experiment here if it does damage. I'm about 800 miles with the maxlife and the level has barely budged but then again this car has given me false hope way to many times. I went against conventional wisdom with the 0-20 simply because when I used heavier weights, the consumption increased.