Little secret. There is no such thing as a "Standard OCI Length". Oh, there's a number in the book based on Joe Average, governmental whims, current warranty length and whatever else makes a buck and allot of marketing. That circles back to the $$$$.
First clue is that the number does not change during the life of the vehicle. The two biggest choices you will make most don't even consider. Ring seal and base oil type. All other things equal, and they never are, those two items set the oxidation rate (for a given temperature) the oil will experience. Blow by gasses load the oil with oxidation precursors and the base oil type resist those changes. The more oil you motor uses that is caused by ring seal loss the shorter the life of the oil. That doesn't mean that a motor that doesn't use oil doesn't need an oil change. ALL motors use oil. When someone, like myself, says, "my motor doesn't use oil" it means that by the time I change my oil, it hasn't used an amount I can measure.
Now you don't actually choose ring seal, but you chose, or don't, to adjust OCI length accordingly. Machines are cleaver like that. They respond to exactly the inputs you give them in a very predictable way. We just are not well informed enough to understand the language they speak. Like a baby, it can't tell you it has a tummy ache but if you are in tune with the child you can figure it out. Right?
A lot of things can condemn an oil. Some are obvious. Glycol contamination from a blown head gasket will get you to change your oil even if you changed it yesterday. Some are less obvious. Fuel dilution related viscosity break. Additive depletion. Rapid oxidation caused by the increased blowby of heavy loading, towing, high speed and increased temperature of the oil for the same reason. Excess water loading from winter driving and short tripping. Frozen PCV or ineffective CCV orifices. Leaky injectors even in dry MPFI systems. Worse, HPFP leaks in GDI engines. List is endless and most of it has nothing to do with the health of the motor and much to do with the environment it lives in and is operated under.
Those differences start arguments when one fella who treats his machine X has no issues at recommended OCI and another has nothing but issues but treats it like Y. Or guy one uses a PAO/POE based oil and the other a mineral straight cut solvent dewaxed oil.
Everything matters and nothing is standard. This leaves a guy with three choices. 1.) Do what you've always done and get the result you've always gotten, hopefully. This is what most choose to do 2.) Test to FIND the correct length for your service and monitor once in a while or when conditions change. 3.) Use really short OCI's.
I'm 70. My 95-year-old father has run a few motors well past 750,000 miles on mineral oils that 'used no oil' and were as clean inside and the day they were built. Trick? 1K mile oil changes. On mineral oils from the late 1930's to the mid 1970's. His first car, a 28 Model A was changed every weekend and bulk oil strained through cheese cloth. LOL. Ah, what the heck. Oil was cheap then. Under a buck a quart when I started driving.
Well, likely more than most will read these days so I'll stop here.