I totally agree. I'm a stickler when it comes to a manufacturer's requirement or recommendation for anything, not just cars. I was taught by a former boss once that the manufacturer of an item nearly always knows the item best, and to deviate from their recommendation requires a very sound reason that comes with a lot of justification.
Like I said though, I was just intrigued by the OP's statement that the specific grade was required for warranty. That's not done very often and it caught my eye.
Originally Posted By: 440Magnum
Originally Posted By: kschachn
A sound recommendation, one that I would follow as well. I was just intrigued by your statement that it was required for warranty, a specific grade requirement is unusual for an OEM. The Chrysler spec would be more common.
I'm not an internet lawyer, but when there's a table in the owner's manual that lists a viscosity grade for the 3.6 engine, a viscosity grade for the 5.7 engine, and another grade for the 392/6.4 engine, I would take it as a given that running the "incorrect" viscosity might raise a warranty question if the manufacturer or dealer ever decided to be snarky about it. The Chrysler MS-xxxx spec would fall in the same category, but since its just an endurance test there is no chemical analysis could ever hope to prove that an oil did or did not meet it. On the other hand, a cheap UOA can tell if the oil was in or out of the viscosity grade stated in the owners manual... so IMO it would be a lot riskier to run the "wrong" viscosity than it would be to substitute, say Mobil 1 that doesn't currently carry the MS-xxxx taxi fleet test spec for Pennzoil Ultra that does carry it.
For me personally, I assume that just because I change my own oil (despite keeping receipts) I might have to engage in some sort of argument to make a warranty claim involving the oiling system... let alone the fact that I use Mobil 1. That said, the odds of an engine problem with a modern Hemi are already tiny, especially in a stick-shift car that doesn't have MDS and therefore the timing chain recall issue is off the table. The odds of a specifically oil-related failure during the warranty period are just about nil. If I'm going to make a warranty claim on the Challenger, it will probably be electrical or computer in nature, not something in the drivetrain. Lots of decisions in car ownership are a calculated gamble, and this is one I'm perfectly comfortable making. YMMV.
