Blanket statements regarding extended oil change intervals without monitoring by oil analysis are irresponsible and do a disservice to the user. Regardless of the properties the oil may have, air filter maintenance, fuel delivery issues, coolant leakage,driving conditions and the specific type of engine all have an impact on the ability of the oil to be left in the engine for an extended period of time.

Advocating time based drain intervals that are many times what one would consider "normal" ignores the condition based maintenance practices that reliability focused maintenance professionals have embraced.

I'm all for extended drain intervals, but it requires an investment in time and energy with monitoring an integral part of the program.