Can a dealer determine what weight oil your using?

[The Critic]

Nearly all approvals do that because the approval specifies a minimum HT/HS. Actually Mercedes-Benz is one that’s moving away from allowed grades, which makes sense because the approval specifies HT/HS and that renders a grade irrelevant.

That is not entirely true anymore. Take a look at this example from Mercedes from the current generation GLE450e plug-in hybrid:

229.52 oils can be 0w-30, 0w-40, 5w-30 or 5w-40 -- all of which have a minimum HT/HS requirement. However, MB clearly states to only use a 0W-40 grade in this application.

 

[kschachn]

That is not entirely true anymore. Take a look at this example from Mercedes from the current generation GLE450e plug-in hybrid:
View attachment 259953
229.52 oils can be 0w-30, 0w-40, 5w-30 or 5w-40 -- all of which have a minimum HT/HS requirement. However, MB clearly states to only use a 0W-40 grade in this application.

? That’s what I was saying. That specific one is directly related to the oil that was used for fuel economy and CO2 emission testing. The approval requirement is still the HT/HS.

 

[PandaBear]

I am curious how they measure the "grade" on vehicle. Do they have additional sensor or is it just an algorithm that measure since you last reset your maintenance counter?

 

[Jetronic]

Even in a warranty situation?

If you used an oil thin enough to cause serious damage they might, but only if there's no service history.

 

[Jetronic]

I have a new 2023 Ram, and it calls for 0w20. Previous year Rams call for 5w20 or 5w30. I'd like to run the 5w30 and not have to worry about the warranty.

going thicker won't cause oil related issues, there would not be a need to test for oil viscosity.

 

[D1dad]

After seeing the thread where Mazda denied warranty work over 600 miles why take a chance. The only 3 of my Nissans that allow an alternate grade is my 18 rogue. “5w30 conventional is allowed if 0w20 isn’t available”. My 21 specifies gf5 0w20, my 24 is specific to gf6 0w20. I’ll stick with what the manual says until I get to 60k. There’s plenty of high end oils in that grade that meets spec and no need to have a standoff with the manufacturer.

 

[CarbonToast]

If I took my vehicle into the dealer for a suspected warranty issue. Say as little as possible. If they ask, I changed the oil with what it says in the manual. More questions, plead ignorance.

Dont T Up a battle with the service manager.

 

[TiGeo]

They could certainly ask for receipts showing maintenance/oil changes if you had a major engine issue. They could run a UOA and see grade. Whether that is done or could impact the dealer or manufacturer approving your claim is something nobody here can say. This post is repeated here ad-nauseum with '00s of responses arguing the details in hypothetical situations and again..nobody here can actually answer it as it will be situationally dependent with your dealer and the manufacturer. Do a risk assessment and make a decision. Warranty denial often can be handled through arbitration which doesn't require an attorney - check your owner's manual/warranty booklet. It would be strange to get denied with regular and substantiated service to your vehicle in that event for using a higher grade oil than the book recommends/calls out but again....nobody can say that with 100% certainty. In fact, it would be strange to ever have an instance where a well maintained engine had catasrophic engine damage requiring this convo anyway.

 

[hemioiler]

I have a new 2023 Ram, and it calls for 0w20. Previous year Rams call for 5w20 or 5w30. I'd like to run the 5w30 and not have to worry about the warranty.

Do you plan to keep the truck for a long time? If so, I'd worry more about the period outside your warranty, so I ran 5w-30 from pretty much brand new in my truck. The vast majority of hemis have 0 issues inside warranty, if you feel the truck needs/benefits from a w30 or w40 then I'd suggest you go for it. Even if your truck experiences engine issues, they're not likely to blame the viscosity unless you did something really extreme.

 

[Astro14]

With that said, on certain applications, MB is starting to state that only certain grades within an approval are allowed.

True - but what you tell the car you put in, via that interface, and what you actually put in, could, potentially, be different….

 

[Patman]

If someone is really that worried about having an issue with a warranty claim then they should just get all of the oil changes done at the dealer. There’s no way they can deny any claim if you do that (and follow the recommended OCI of course)

That being said I have never done that with any of my new cars, I have always done my own oil changes. I have often asked the dealer when buying the car and they assured me that as long as I kept the receipts for the oil that there would not be a problem. Luckily I have never had an engine problem ever in 39 years of driving.

 

[SimpleSyrup]

It doesn't matter if you have receipts, service history or what. If you roll in with a sludged up engine, warranty denied. If the engine is clean, the internals clean, and zero history of dealership oil changes, not an issue. So much ink spilled worrying over these warranty boogiemen. Somehow CarFax has managed to bamboozle itself into the fabric of car ownership much like credit agencies. Foolishly, I bought a car based on this lovely Carfax report once. Great history of documented oil changes, etc.

Car drains oil faster than the Exxon Valdez and burns more oil than a 2 stroke weedeater. Pulled the valve cover and it was so thick with golden varnish that Coronado himself would have drooled with lust. Yeah, I was the sucker who believed the CarFax.

 

[Pablo]

Been doing Amsoil 25+ years now. Never once I have I been or seen or otherwise involved when a car dealer service dept asked for or did a UOA. Never been involved with any oil related issue, scuffle, side bar, or wrestling match either

I have seen some mentions here, but nothing but words.

 

[ARCOgraphite]

I have a new 2023 Ram, and it calls for 0w20. Previous year Rams call for 5w20 or 5w30. I'd like to run the 5w30 and not have to worry about the warranty.

What engine? What state do you live in ? Do you have MDS and and ECO light? Do you tow?

edit: addendum: My old trick when I change oil was to run 5W20 and add in a quart (or two for a truck sump) of same brand/line 5w30 or 10w30. Have receipts for the proper volume of oil for the oil change, but keep a "secret" and "undisclosed"jug of the thick stuff to "substitute" in. Not add on top - but SUBSTITUTE some for the lighter 20 grade.

 

[radiometer]

If someone is really that worried about having an issue with a warranty claim then they should just get all of the oil changes done at the dealer. There’s no way they can deny any claim if you do that (and follow the recommended OCI of course)

That being said I have never done that with any of my new cars, I have always done my own oil changes. I have often asked the dealer when buying the car and they assured me that as long as I kept the receipts for the oil that there would not be a problem. Luckily I have never had an engine problem ever in 39 years of driving.

On a recent car purchase where 5W/20 is shown as required I talked with the service manager. My question with him was about whether I would void the warranty by using a 5W/30. He assured me that my using a 5W/30 would not have any effect on the warranty.

 

[The Critic]

True - but what you tell the car you put in, via that interface, and what you actually put in, could, potentially, be different….

Correct. I mean, I have enough oil receipts where I could paint a believable picture of only using approved oils when I may or may not have been running Homebrew...

 

[buster]

They could certainly ask for receipts showing maintenance/oil changes if you had a major engine issue. They could run a UOA and see grade. Whether that is done or could impact the dealer or manufacturer approving your claim is something nobody here can say. This post is repeated here ad-nauseum with '00s of responses arguing the details in hypothetical situations and again..nobody here can actually answer it as it will be situationally dependent with your dealer and the manufacturer. Do a risk assessment and make a decision. Warranty denial often can be handled through arbitration which doesn't require an attorney - check your owner's manual/warranty booklet. It would be strange to get denied with regular and substantiated service to your vehicle in that event for using a higher grade oil than the book recommends/calls out but again....nobody can say that with 100% certainty. In fact, it would be strange to ever have an instance where a well maintained engine had catasrophic engine damage requiring this convo anyway.

 

[Shel_B]

Some approvals do contain tracers which might facilitate a field determination that the oil was not approved.

Didn't Volswagen do that with some of their approved oils?

 

[DuckRyder]

Yes.

 

[The Critic]

Didn't Volswagen do that with some of their approved oils?

Yes, VW 508 oils.