Why are some things posted, re-posted and re-posted.....
We've already established this: There is NO difference in the engine "tolerances" between those that recommend 5-20 or 20-50. In fact, we've seen both recommended for the same engine depending on the continent.
Secondly, as far as wear numbers are concerned. I've already said...UOA DO NOT show the whole picture. I've used 5-30 oils in a vehicle recommending 10-40/20-50 and the like. After 60-80k, the amount of sludge due to burn-off and consumption was unacceptable. Will I go back to a 30 weight? Forget it. And neither will places like Australia if you guys think that adding 1qt/3k miles or more is normal...because it's not.