It may be interesting to hear but irrelevant if the manufacturer specifies oil X and you used oil Y b/c all they have to say is "they didn't follow the manufacturer's recommended blah blah blah".
Looking for first person story: My warranty denied because of oil used
- Thread starter ammolab
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I've never been a big warranty guy but also have never had many large issues during the warranty period on the vehicles I've had with one. Never had a problem getting the bits/bobs I needed fixed fixed under warranty.
Easy to just whip out your records. I have a folder of all receipts with a corresponding spreadsheet on every vehicle I have/have owned. Always was a nice thing to hand the new owner private-sale. Only traded one car in in my life but will again at some point and will put them in the glove box.
And if you don't read and follow what you buy which I'm sure requires maintenance records be kept, well...you get what you get on that.
We had a long thread on this topic a while back, and no one was able to quote an owner's manual or warranty booklet where it said that using an oil of a grade that's higher than recommended would violate the new car warranty. Using a grade that is lower may however, since this can cause an oil-related failure. But no oil of a higher grade or HT/HS will cause a failure.
And bottom line, why would a manufacturer say that? There is no technical reason for doing so, as has been shown here many times the language in the owner's manual is driven by the requirements of their CAFE award letter. The manufacturer must strongly discourage the use of any oil grade other than that which was used to obtain their fuel economy test results. In fact that discouragement goes beyond the owner's manual.
There are no advantages to thinner oils other than a slight fuel economy increase. The manufacturers aren't idiots and know this. There is no real mechanical need for a thinner oil in regards to engine failure. This is a huge myth promoted by some who are just fear mongering without basis.
And bottom line, why would a manufacturer say that? There is no technical reason for doing so, as has been shown here many times the language in the owner's manual is driven by the requirements of their CAFE award letter. The manufacturer must strongly discourage the use of any oil grade other than that which was used to obtain their fuel economy test results. In fact that discouragement goes beyond the owner's manual.
There are no advantages to thinner oils other than a slight fuel economy increase. The manufacturers aren't idiots and know this. There is no real mechanical need for a thinner oil in regards to engine failure. This is a huge myth promoted by some who are just fear mongering without basis.
Warranty denied? no. With so many synthetic long drain oils on the market I imagine lubricant related failures are extremely rare on an in-warranty vehicle. Today is much different than say 20 yrs ago when shelves were full of conventional or semi-syn and only a few automakers were pushing OCI's out past 10k miles. Back then, especially with the Euros, some engines were designed around a min HTHS in either a 30w or 40w, and the problem was that there were only a few 30w oils on the shelves which met the min.
Today oil grades revolve around CAFE. This doesn't mean that the 20w oils are insufficient it just means that the automaker won't encourage someone to use something thicker than what the vehicle was certified with.
4WD
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That’s fine - if I have a differential failure - have a picture of “silver paint” oil at only 17k … Along with pictures of what went in and the odometer - the iPhone time stamps them - not me … Even do this with batteries once installed etc (old & new) …
Be happy to take that to small claims court … Dealers are making big money in the service bay …
(kept some alive in recent months) …
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4WD
$50 site donor 2025
In my case - I’d bet the farm that non Dexos would be an issue way before which of the two common Dexos-1 grades
Agreed. But if you read any of the CAFE award letters it's far more than "won't encourage", it must be active and extensive discouragement. It extends to marketing and guaranteeing oil grade availability in the marketplace.
Had a compressor company attempt to deny a claim but it went through. Oil analysis indicated a fluid other than OEM was being used, we developed an issue, a bearing noise I think, they tried to deny warranty. When we showed them the invoices where their tech had been doing the maintenance since new all of the problems went away.
Toyota Owner’s Manuals has wording to the effect it will not void warranty claims based on a lack of documentation, but only if there has been a lack of maintenance. As Toyota dealers have no way to distinguish, say, 5w-30 in a sump vs 0w-20 and don’t require oil purchase documentation (which is easy to manufacture anyway), barring obvious sludge or early varnish, oil grade shouldn’t make a difference.
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Worked at a Chevy dealer and they’d pull oil samples on blown engines sitting there on the floor waiting for warranty approvals. Warranty reps absolutely giddy to deny a claim. Techs sitting there waiting for approval to do the work. Car would be pushed outside for the wait.
And again (Chevy dealer), tech I know would only have his oil changed on his Silverado at the dealer while it was under warranty because he had seen warranty denials due to oil.
And again (Chevy dealer), tech I know would only have his oil changed on his Silverado at the dealer while it was under warranty because he had seen warranty denials due to oil.
I mean sure, it's obviously easiest for record keeping to have all your maintenance while under warraty done at a single dealership but it's not necessary and quite the internet boogieman that for some reason you will not only have a catastrophic engine failure if you just maintain your car at the most basic level but on top of that your DIY records or Jiffy Lube receipts won't be enough to substantiate your claim. This is just crap I don't worry about but makes for fun internet forum fodder.
twouvakind
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No f's given by most places like Carmax, Carvana, etc. Any dealer giving you a hard time on a trade in for maintenance records is just making up reasons to not give you what you want is all. It's not like they pass those records on to the next owner.
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Because it was a 2021?
It's kinda already been said, but I'm a fan of echoes.
In this case, the manufacturer wouldn't need to prove the higher viscosity oil did damage. They would just need to show that their warranty is based on the use of a xW-16 or xW-20, and their performance/longevity claims cannot be held subject to an 'untested' grade.
"but but the guys on BITOG said it would be fine"
But it’s not. Besides that, the oil would have to be the cause of a failure and no engine is going to fail because of the use of a somewhat higher HT/HS oil.
They also said on BITOG..."run it with confidence !"
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