The low hanging fruit for a jeep dealer to deny a warranty claim is modifications and off roading. Proving an oil related failure is next to impossible because it’s next to impossible.
For the Pentastart 3.6L, just about any lube meeting API SP is going to work for 3k miles. That is a VERY short OCI duration in today's world.
Even the basic ST or other house brand would be fine; safe and effective at controlling wear and contamination for the exposure you're indicating.
As for the topic of your thread (warranty voidance), you need to research all the threads on this site regarding discussion about the Magnuson/Moss warranty Act. I also suggest you spend more time on the FTC site to learn about warranty terms, and then read the Amsoil warranty for yourself, and make your own determination. It is my opinion that Amsoil would not void the OE Jeep warranty, but you need to make up your own mind after doing your own research.
That might be true. It certainly is not knowable. It is not something that can be determined with a simple UOA. But as stated Amsoil OE would still be in fine shape at 2X that as would Platinum and most any modern synthetic oil.
Amsoil does say Chrysler MS-6395 in the back of the bottle, but people say that is not a real certification like from Pennzoil and Castrol etc. I am confused.
Technically it's possible. For example if the Chrysler cert revolved around emissions protection, your car is an oil burner, and your catalytic converter failed, Chrysler "could" void the emissions warranty on the cats because you used an oil which poisoned them. If you used a conventional oil and because you went the factory interval the oil sludged up, Chrysler could deny warranty work on the now sludged engine. If you used an oil of the incorrect viscosity (ex, 0w16, 0w8) then ya Chrysler could void your warranty if they decided to send the oil off for sampling.
API limits the amount of certain additives within fuel efficiency grades (30 grades and lower). Amsoil and others like Redline, HPL, will exceed those limits in order to extend the run time and cleanliness of the oil at the expense of cost. You'll also see from the majors (Mobil 1, Pennzoil, Castrol, etc) who sell a Euro blend in certain grades.
Example, Mobil 1 FS 5w30 doesn't meet API SP because of the slightly higher level of certain additives but it meets the performance requirements of API SP.
Also more of an additive isn't always better. The version of additive is also important and a UOA won't tell you the version. You don't use UOA's to discern performance differences between oils.
Amsoil does say Chrysler MS-6395 in the back of the bottle, but people say that is not a real certification like from Pennzoil and Castrol etc. I am confused.