Probably just me being paranoid. 20 weight (and new 16 weight) oil is fractionally better for corporate average fuel economy ("CAFE") standards set by the government, but that does not mean that it is best for engine life. The first vehicle I purchased that spec'd 20 weight oil was my $17,200 2008 Honda Civic. That same year, high-end Ferarris and BMW "M" series performance vehicles were rolling off the assembly line with Shell Helix Ultra synthetic 10W-60 oil as factory fill. Am I to believe that my cheap Civic's motor was built to higher standards and "tighter tolerances" than a $400k Ferrari?
BMW went to 10W-60 in their S54 engines because they had a problem with rod bearings failing, it was a band aid approach to a design deficiency that didn't really work. If it had been designed correctly from the beginning there would be no need for that oil.
I'll go out on a limb and say a Civic motor is almost certainly built to "higher standards and tighter tolerances" than the Ferrari engine. How many Ferrari's do you see regularly going to 300K+ miles like a Civic? More expensive doesn't mean better.
