The post is on what I found among various blogs on this topic...and those invariabily turn into thick vs. thin posts. What would answer the question is finding out of those engines over 15 years that used one weight or the other, which generally had a higher % wear and/or failure rate. It might only be a 45-55% or 40-60% split to one side. But, without mass tear downs, we'll never know as it doesn't benefit anyone to spend the considerable $$ find it out. We're not looking for mass failures....only which method works significantly better than the other. And 45/55 would be significant....just like in elections.
Originally Posted By: tig1
If the subject here is about excess engine wear with 20 wt oils then the UOAs don't show that. With the millions of engines using 20 wt oils, why don't we hear of mass engine failures over the last 15 years. This appears to be another "thick vs thin" post. Notice the UOA section on page 1 of the Merc GM 4.6 UOA using 5-20.