You guys rubbing off on me. After using Amsoil for past O.S.A.s years ago, and then deciding not needed... I am ready again. You guys good advice and use of the O.S.A. has prodded me to jump on that train again. Thanks to all of you. You made me realize how important the O.S.A.s can be as "proof" if needed for warranty - recall issues down the road. Plus simple piece of mind to assure me that how I am servicing my auto is a good or bad thing. So, I am looking for your preferred "independent oil sample analysis company and why? If anyone does not mind sharing? I know of Blackstone ,Baldwin, WIX? and a few others. Any preference for ... quality / price / convivence / customer service etc...?