buster, the majority of thinning 0W-40 used oil analysis we have here on BITOG are from folks running it for extended durations in turbocharged engines, not because it's a 0W-40. Wouldn't you agree that turbos are harder on any oil than a non-turbo will be? For two extended 0W-40 N/A applications I've seen here, an Impala ran it flawlessly for over 7k miles (only down to 14.2cSt) & a Tacoma was exceptional at 10k miles (down to 13.4cSt).
Also remember, grades aren't on/off switches. You need to look at everything that's going on in a sample, not just the generalized thickness category.
Also remember, grades aren't on/off switches. You need to look at everything that's going on in a sample, not just the generalized thickness category.