TIMER: With regard to the ACEA A1 , A5 and A3 specs, I believe SynLube will meet them. I don't know what these specs mean but if the company put those specs there, it must mean that they stand behind their oil for use in engines for which these specs are relevant. I suggest that since you doubt this, you should e-mail SynLube requesting a clarification. When I was considering the use of SynLube, I had questions and he patiently answered them. More than anything else, it was his answers that prompted me to try the product.