Warranty denied due to oil viscosity.

[Graham Piccinini]

There are 10+ posts a day here about possible warranty denial due to oil viscosity, but how realistic is this fear? How often do you hear about a warranty being denied due to an oil viscosity that is different from the CAFE recommendation?
Realistically how often, if ever, do you see a daily driven car have an engine failure due to having 5w30/5w40/5w50, 0w30/0w40/0w50, 10w30/10w40, 15w40/15w50 or 20w50 instead of 0w20/5w20 listed in the owner's manual? Post examples here please, if you have any.



P.S. Please exclude engine failures that include complete lack of common sense... For example:
- Using straight SAE30 in a middle of winter in Alaska without a block heater.

OR

- Using 0w20 in a highly modified 800hp 4cyl on a track day.

 

[hpb]

Warranty denial - never.
Engine failure - never.

 

[Cujet]

Interestingly, the use of heavier viscosity than 0W-water, in some trouble prone engines, results in longer engine life and therefore less chance of a warranty claim.

 

[Hall]

My question is, short of the owner telling the dealership, how will they know what the viscosity is ? They are not going to test it and even if they did, I think the analysis labs will tell you their testing isn't 100% when it comes to determining viscosity.

 

[4WD]

Originally Posted By: hallstevenson
My question is, short of the owner telling the dealership, how will they know what the viscosity is ? They are not going to test it and even if they did, I think the analysis labs will tell you their testing isn't 100% when it comes to determining viscosity.


Who thinks the dealer has an issue with the OEM paying for engine and labor if abuse can’t be proven.

(Assume they all have a black box)

 

[benjy]

your ambient temperature + how you drive should govern oil choice NOT one size fits all for EPA mileage test that in some conditions is a POOR choice!!!

 

[Artem]

Originally Posted By: Cujet
Interestingly, the use of heavier viscosity than 0W-water, in some trouble prone engines, results in longer engine life and therefore less chance of a warranty claim.


0w-water. I LOL'd so hard. Thank you.

 

[faltic]

how am I missing all these posts

Originally Posted By: Vladiator
There are 10+ posts a day here about possible warranty denial due to oil viscosity

 

[Artem]

Originally Posted By: benjy
your ambient temperature + how you drive should govern oil choice NOT one size fits all for EPA mileage test that in some conditions is a POOR choice!!!


Well said. My Toyota Celica GT-S spec's 5w30 but I run 10w40 in it, especially right now during the summer because that's what Lotus recommends for the Elise which has the same 2ZZ Toyo/Yamaha engine. I beat the [censored] outta mine daily and want the thicker oil film. Engine runs quieter (this was instantly noticeable after switching from 5w30)

Driving style and conditions should warrant a slight change from the factory recommended spec.

 

[Artem]

Originally Posted By: faltic
how am I missing all these posts

Originally Posted By: Vladiator
There are 10+ posts a day here about possible warranty denial due to oil viscosity



People always say not to change viscosity while under warranty, blah blah blah. Typical nonsense which is why you're missing these posts. Your brain auto-blocks the cry-babies.

 

[PimTac]

More fishing.

 

[Dyusik]

Originally Posted By: faltic
how am I missing all these posts

Originally Posted By: Vladiator
There are 10+ posts a day here about possible warranty denial due to oil viscosity



It is a reflex comment, that sounds like :
Warranty blah blah follow you manual
Warranty blah until it's out, then use [insert more appropriate viscosity for application] blah blah
I don't want to use XwXX because blah blah warranty blah
Engineers are so smart blah blah and can't blah warranty blah
But you will blah blah warraty


Posts, as in posted replies within a topic.

 

[Trav]

The problem with the warranty is the receipts showing the viscosity shown in the owners manual. They will deny warranty for a lube related engine failure if you cant produce them.
No they are not doing a UOA or anything else if the oil looks fluid.

 

[Dyusik]

Originally Posted By: PimTac
More fishing.


Not necessarily, this very thought comes to mind when someone pops off with a "But your warranty will be void!" nonsense.

 

[Danh]

Originally Posted By: hallstevenson
My question is, short of the owner telling the dealership, how will they know what the viscosity is ? They are not going to test it and even if they did, I think the analysis labs will tell you their testing isn't 100% when it comes to determining viscosity.


If the dealer asks for oil change documentation (e.g. WalMart receipts), they will almost always show the purchased oil’s viscosity.

If the spec was 0w-20 and the receipts said 5w-30 would they make an issue of it? Probably not. Documentation can be faked or misused and may not be what was really put into the engine, so they may not view it as a reliable guide in the first place. More likely they’d see how clean the internals looked and if there were no signs of neglect, just move on.

On the other hand, if the dealer was under warranty claim pressure from the OEM they could decide to be jerks about it and make life difficult. The OEM might overrule the dealer or might not. And yes, the OEM supposedly would have to “prove” the wrong viscosity caused the engine damage. But they have lots more resources than we do.

 

[SteveSRT8]

Originally Posted By: PimTac
More fishing.


Totally

 

[Rand]

click bait title.

I figured you had one denied.

Nothing to see here.

 

[philipp10]

Originally Posted By: Cujet
Interestingly, the use of heavier viscosity than 0W-water, in some trouble prone engines, results in longer engine life and therefore less chance of a warranty claim.


Is this a true statement? I remember reading, on this site in the Oil University section that the wear saved from cold starts with thin oil was greater than the wear saved from a heavier viscosity.

 

[tomcat27]

Any good mechanic or engine builder can tell the cause of an engine failure. I have a friend who was denied warranty coverage on a leased Durango. It was sludged. The dealer did not ask for receipts nor would they have even considered them. The same person did get warranty coverage on a rebuilt engine, although the rebuilder did do a UOA. There was significant fuel dilution due to an poorly operating choke. The builder covered it anyway, but he said he always does UOA on warranty claims.

 

[Bladecutter]

Originally Posted By: Cujet
Interestingly, the use of heavier viscosity than 0W-water, in some trouble prone engines, results in longer engine life and therefore less chance of a warranty claim.


I would like some proof on that.
A nice highly controlled, scientific A versus B test from a reputable source would be wonderful.

Same brand/variant of oil used in both engines, under identical operating conditions, with identical driving and change habits, just in two different viscosities.

Please provide at your earliest convenience.

BC.