I had an independent service shop do a 24 hour piston soak on my 245,000 mile Prius with great results. The tech said I had a couple of leaky fuel injectors and the other 2 were weak. I took the car to Toyota stealer and had the injectors changed out because the leakers were washing down the oil protection on the cylinder walls. My oil consumption has dropped to almost nil. My dipstick is showing down about 1/4 quart after 2200 miles since the above fixes were made. This is a huge improvement over the previous experience of needing a quart every 500 miles or so. I am posting this as a possible fix for those of you who are having consumption problems with engine oil. The soak cost about $110, mainly because it tied up a bay for a full day.
I googled prius piston soak. Will keep this in mind. 2007 Prius Piston Soak | Bob Is The Oil Guy 2008 Toyota Prius piston soak | PriusChat
Seafoam is just isopropanol with a splash of petroleum distillates. Buying 99+% isopropanol/2-propanol online is probably a better deal than $eafoam.
Page 2 of seafoam motor treatment safety sheet disagrees: https://seafoamworks.com/uploads/2019/09/SDS-SFMT-US-ENG-v20190905-1.pdf
It is less than 25% isopropanol, according to the safety sheet. As HAL would say, this conversation can no longer serve any useful purpose.
