So my wife is at our local Dodge dealer right now to buy a new oil change package for our 2018 Jeep Grand Cherokee with the 3.6L Pentastar. They are telling her it calls for full-synthetic 0W20 oil - the package is $145.00 vs. $100.00 for semi-syn. I end up talking with the service manager who tells me I might be out of luck if there is an engine failure while running semi-synthetic oil - the car is certified, so it has a 100k drivetrain warranty. So I asked when Chrysler changed oil requirements on the 3.6L, because they use semi-syn in my 2016 300 that also has the 3.6L motor, & same with my two other previous 300's (a 2012 & 2014) that also both had the 3.6? He could not tell me when these engines started requiring the full-syn.

So the question I have is this: is what they are telling me legit? I have never heard of this scenario before. This same service manager also tells me he has never heard of ANY valvetrain issues with the 3.6 engine. I think this guy is FOS.