hello
I had gli 2008 may model (old shape). I was using 20w-50 oil plus i also used to pour in STP one box.
One day I bought CERATEC and put half in my Toyota Indus during oil change and half in my 2008 gli. The effect of even half bottle was quite good and my car became smoother. Then after around 3500 km i changed the oil and used 10-40. And my car was running quite nicely with better pick with this oil. And i was thinking about shifting to 10-30 but before that i sold off my car.
now i only have toyota indus and i am using 10w40 oil in it and after one more oil change i am going to try 10w-30 in it. What do you think?