Seeing as I was just asking in a previous thread about your favorite brand of oil. I got really curious about oil additives. Have you ever used it? Do you like it? Does it actually make a difference? So many questions......lol
The owners maunal calls for oil changes every 10K miles. US culture loves to change the oil often and European culture ...not so much. If Toyota can warrranty a car and only change the oil every 10K miles, that tells me alot about the actual need to change the oil. They would surely reccomend additives and more frequent changes to avoid all those warratny claims wouldn't they? Much cheaper for them and they would make more out of the servicing costs.
I used it before.....made my oil too thin. I started hearing a knock in my engine so I did an oil change with fresh oil and the knock went away. Never gonna use it again. Not worth the risk of damaging your motor.