Well, I got my Kreen yesterday and put some in my '99 Subaru, to see what will happen.
I also put about 3 oz. of Kreen in this old mower that has a 15 hp B&S engine. This old motor smokes and burns oil so bad, that it changes itself.
I left the thing running in my tractor port for about 45 min.. When I came back to check on it, smoke was boiling out of the building! This thing began to backfire, sounding like a 12 gage shotgun going off!
The motor quit after backfiring many times and I when went in to pick up the parts the motor was still together,LOL
I changed the oil, cleaned the plug that was full of black gunk, and this thing cranked right up! It runs ok, but still smokes, some.
I hope my old Subaru will handle Kreen somewhat better than my mower!