Viscosity: Engine protection Vs. enhanced mileage

What company has the best reputation for durability? Answer: Toyota.
What company specs the thinnest oil in the industry? Answer: Toyota.
Toyota as a company spec everything from 0W16 to 15W40 in the same engine.

 
Wow…as a long-time reader but first-time poster, in my debut week here I’ve already been promoted! A few days ago, I couldn’t even spell “Troll,” but today, I are one…uh-huh, uh-huh! Only in America can a newbie skyrocket to such lofty heights, LOL.

Seriously, thanks for all the prompt and thoughtful replies to my original question. It has been helpful, and hopefully helpful to others who likely have the same thoughts and questions. All of your replies have been good food for thought.

For those who, like me, care a lot about how motor oil affects your vehicles (this is the BobIsTheOilGuy forum, after all), I HIGHLY recommend you watch the Video linked in Post #4 above. Yes, it is long; trust me, it’s worth it. As suggested there, the viscosity question is specifically addressed in a shorter segment starting at the 18 minute mark, but if you really want a broad range of scientific, data-driven, straight-talk information that overcomes decades of snake-oil (pun) marketing, brand name prejudice, and perpetuated myths about engine oil…just watch it. I have been a car enthusiast for over 60 years. I read and study a lot, and I probably gained more unbiased, fact-based info about motor oil in that one video than from 6 decades of other sources.

So, my action plan going forward:
Although there are only 27,000 miles on my Lexus, I have only 9 months left on my 48 month/50k mile factory warranty. I just changed my oil using factory-specified 0w-20. When I drain the oil next time, I will get an oil analysis (fingers crossed it comes back with <5ppm wear metals). With the warranty expiring, I will then try a couple changes of Pennzoil Ultra Platinum 5w-30, then get another oil analysis to see if wear metals decrease.

As Carlostrece points out in post #20 above, PUP is on the very thin side of a 30 grade. If I don’t see a meaningful decrease in wear metals with this -30 grade, to pursue a tiny bump in fuel economy I will consider switching down to a 5w-20, perhaps to a different, premium formulation with viscosity on the higher end of the -20 grade versus the PUP. After an oil analysis on that third option, I should have enough comparative data to decide on a long-term product that best meets my vehicle needs and driving conditions.

I realize this whole, exploratory process is picking nits. Any premium, 0w-20 on 4000 mile drain intervals isn’t going to trash my engine; I just wonder if it is the very best I can do for long term reliability. My other vehicle is a 20-year-old, Town and Country minivan I’ve had since new. Currently using 5w-20 Pennzoil Platinum High Mileage, it’s never required any internal engine work, it runs like a top and consumes very little oil. As I said, I keep ‘em for a long time so expending the effort to find the best engine protection possible seems worthwhile.
 
No Toyota recommends 0W16 or 0W20 or 5W20 or 5W30 or 10W30 or 15W40 as printed in the factory manual

Toyota uses 0W-16. It says so in the manual.
Oil Grade: 0W-16

"oil one grade higher may be used for high speeds or extreme conditions". That's not what's installed at the factory, though.
 
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The Honda owner's manual specifically states you can use a synthetic oil if it is labeled with the API Certification Seal. Amsoil and HPL do not have the seal, but "meets or exceeds" the API specs. Should this cause concern under warranty? My understanding of the Magnuson-Moss Act is that the burden of proof the oil caused the failure is upon the servicer/dealership, but we know how that can go. Amsoil has their own warranty and will back you up when using their products, but what about HPL or others not having the donut? Thanks.

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Added - I couldn't find a beating-a-dead-horse emoji. My apologies.
 
The Honda owner's manual specifically states you can use a synthetic oil if it is labeled with the API Certification Seal. Amsoil and HPL do not have the seal, but "meets or exceeds" the API specs. Should this cause concern under warranty?

I've mentioned this again and again on this forum, and NOBODY, has ever been able to provide evidence that a dealer will deny warranty based on the type of oil used. Yet, again and again and again and again (to infinity) we have people here panicking about only using the grade of oil in their manual "for warranty".
 
I've mentioned this again and again on this forum, and NOBODY, has ever been able to provide evidence that a dealer will deny warranty based on the type of oil used. Yet, again and again and again and again (to infinity) we have people here panicking about only using the grade of oil in their manual "for warranty".
It's a bit late for me to bother panicking. :rolleyes: Changed to Amsoil SS at 494 miles and will be making this switch soon.

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The only scenario I've seen where a warranty claim was denied due to oil was actually a cluster of claim denials that all were later overturned. It involved several Gen 3 Ecodiesels which spec an MS-12991 oil (similar to ACEA A3/B4) with Pennzoil Platinum Euro 5W-40 as the OEM fill. Owners coming to the Dodge dealerships for oil changes were getting Rotella T6 5W-40 because the techs weren't paying attention to the spec. The result was a slew of trashed bearings. Since the incorrect oil was in the sump, Dodge was denying claims. They overturned these when it became clear it was the dealerships installing the wrong oil, not the fault of the owners.
Is the T6 that much different than a Euro formulation? I ignore the FCA spec recommended for my 6.4 Hemi. I just run whatever API SP 0W-40 is on sale. Your post has me second guessing that.
 
What company has the best reputation for durability? Answer: Toyota.
What company specs the thinnest oil in the industry? Answer: Toyota.

The "thickies" give me a chuckle. Move from a 20 to a 40 grade oil? What's the basis? Opinion. No science. "Thin oil is about "the epa" or "cafe". No doubt, fuel economy is a factor, but don't kid yourself.
🤣🤣🤣

Thread 'GR Corolla on track with 0W-20 blows engine and crashes' https://bobistheoilguy.com/forums/t...k-with-0w-20-blows-engine-and-crashes.397277/
 
First off, OEM's spec thin oil, and they wouldn't do that if it put your engine at risk.

Second, nobody is getting denied warranty for using a thicker oil. Is it needed, in most cases NO. But if you feel better, knock yourself out.

And if you run at a track day, I don't care what oil you use, all bets are OFF.
 
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