In my opinion, it's very good for older Japanese engines. The piston rings will worn out eventually for all engines including super reliable Japanese engines. However XADO will fix it at some degree. Of course you need to make sure your engine condition is still good except that worn piston ring.
To keep your engine healthy for Toyota, Honda, Nissan, etc is actually quite easy. You just need to use good oil, change them frequently, use good gas(with advanced clean formula) and DO NOT OVERHEAT IT!!!...
