I am very careful about what i have done to my Lexus. I have had pour in products in the past and never really noticed the difference. I have always thought these things had a placebo effect. I must admit that i am very impressed with your product. My readings were not bad before the service, would have passed an MOT, after the service both the CO and HC were well down, that’s by the by for me anyway, what i am really pleased about is the way it how drives, the car is 12 years old and always been a decent runner since i got it 4 years ago but now it is so much better, smoother , more responsive. Anyway Thank You