Ed:
I believe that synthetic will work the best. If you are interested in using Amsoil, email the Technical Dept. at tech@amsoil.com and I'm sure somone there will give the credentialed reply you are looking for. (I'm at www.lubedealer.com/hiebert if you need it)
Something to keep in mind is that your engine would not be as protected in extreme cold temps compared to when the engine oil is consistantly 10W-30. In my situation I needed to finish filling with my synthetic after I changed oil using 10W-40. I was fresh out so just used a half a quart of...
Reputable oil and lubricant manufacturers should show or give specifications that will have all that information. If you want to doubt their product, that's another issue. Testing these oils after they've been in use is also useful.
This came from a different source, see what you think:
Here is the official description of this type of oil:
Hydro-Refined and Hydro-Isomerized Mineral Oils-
An alternative refining process, which substitutes deep hydrogen treatment for solvent extraction, can yield VI of over 100. An...
Can someone explain in "laymen's" terms what this is? A Drive-thru oil-changer in town adverises that he has this ""Hydro-treated" stuff. Email - rxmhiebert@shaw.ca Thanks.