I seriously question the advisability of using an OLM as the sole factor in oil changes. The lack of a recommended (and REQUIRED!) OCI is very disturbing to me. I realize I'm not the kind of typical clueless consumer (Baaaaaa!) the auto makers AND the government (over)regulators are designing the system to exploit. I buy for the long run.
My reasoning? Very simple:
When the manufacturer is willing to warranty the engine/drivetrain for a period that extends to a STATED life for the car if the OLM's recommendations are followed, I'll believe they have the confidence to "put their money (vs. YOUR CAR'S ENGINE) where their mouth is".
If the trend is to give the consumer a product that is only guaranteed for the warranty period (or a 3 year lease) so that the manufacturer doesn't have to worry about paying for any routine service (i.e. trends towards "lifetime sealed transmissions" or "100,000 mile plugs") you ought to get service and warranty work done free for the life of the vehicle, or for a reasonable stated period, as in 10 Years or 300K miles, whichever is longer.
Otherwise it goes, in my humble opinion, FAR BEYOND the concept of PLANNED OBSOLESCENSE. If a new car is sold as being GUARANTEED for 300K miles and you buy it with 100K on the odo you are buying it with 2/3rd's of its life left. And you can pay accordingly for it, based upon the free market value. If you are buying basic transportation and you need 20K per year for another 10 years, you know what you want/need to buy. If you absolutely must have the newest, "best", most tricked-out trendiest Hybrid Luxury car every 3 years, then you know you are going to have to pay for it, up front, and that there will be a supply of used vehicles with STATED & GUARANTEED lifespans available for the people who don't.
Whether these vehicles are going to be bargains or dead dogs on the market is going to depend on how good a car they really are.
Cheers!
p.s. RE: the OP, I would go the recommended 1st OLM interval and then switch over to one 5-6K OCI, recording what the OLM registered at that point, then go further (as in "until the OLM shows 20% left") with a full synthetic. I just don't trust the auto makers when it is not THEIR money that is on the line.