Hi all...
Just had the first scheduled oil change on my '12 Challenger (SXT, 3.6L V-6)
Question regarding oil type: The owner's manual specifies 5W-30, either synthetic or ordinary.
Packed with my owner's manual was a yellow card called "User Guide Addendum", an official-looking Chrysler form. It says "The manufacturer recommends the use of a full-synthetic SAE 0W-40 engine oil..."
As others have stated, that addendum was not meant for your car, it was meant for a different engine than what you have. Having said that, you can certainly run the 0W-40 synthetic if you want, nothing is going to happen if you do...literally, nothing good or bad will happen. It will behave just like every other oil (that meets the engine's required specs): it will lubricate your engine's moving parts to keep them from seizing up and it will help carry away heat from the internal parts to keep them cool in stop and go traffic and such.
20W-50, 15W-40, 10W-40, it doesn't matter...don't get hung up on those numbers, they don't have nearly as much bearing on the oil's quality and compatibility as it would seem they do. No, you really only need to verify one thing when purchasing a motor oil for your car: If the API starburst on the back is at least SN, you can run it.
Having said all that, I will say that just because you can run 20W-50 without fear of hurting your engine, that does not mean you should run it. There will be some consequences, such as decreased gas mileage, unpleasant noises at startup on cold mornings, etc.
Bottom line: just keep it simple. Buy a good named brand oil that you can afford and keep it changed at least every 5K for conventional and 10K for synthetic. You can certainly have shorter OCIs than those, but you are not going to realize any quantifiable benefits from not using the oil to its fullest before discarding it.
I realize that is going to be a controversial statement there, and I'm willing to suffer the slings and arrows of making it, just so long as it helps get the word out that we aren't living the dark ages of motor oil any more. What we have available to us now is infinitely better than what it used to be. And the truth is, even your average big-box--store's house brand conventional motor oil that only cost $3 a quart is every bit as good as the "synthetics" of 20 years ago.
One benefit the synthetic oil will provide is longer OCIs, if you wish to utilize them. However, if you push your OCIs past 5K (which is the standard interval now BTW), you should run an extended life oil filter to handle the longer time it will spend in duty. Pushing a standard life filter into the 7500-10000 mile range (what synthetics will give you nowadays) is a good way to induce media failure and that ain't no good for nobody. That leaves you with unfiltered oil circulating around in your engine, which is obviously best avoided.
The dealer didn't know anything about the addendum, and after some discussion (they were really nice) I had them put in the original Mopar 5W-30.
Was this person one of the service techs or just a car salesman? If he was a salesman, I would have been really surprised if he even knew what motor oil was, much less why any car might have different specs for their engine's lubrication.
But if he were an actual service tech at the dealership there, then I would have been worried about his lack of knowledge on the subject. Given that it is his business to know, you would think that he'd keep himself up to date on the available info. But if he's just working there until he gets off probation, then he's not going to care to learn anything extra that might benefit the customer.
If it were me, I'd probably find a different dealership to take my car for recalls, maintenance, etc.
...
So I'm still wondering which is right?
The "right" oil is the one that meets the SN rating from API, and which you can afford without having to pawn anything to pay bills. If you can do those and still get the weight it says in the owner's manual, you are golden. If not, don't start panicking or anything, you'll still be okay....I promise.