Oil Weight Recommendation after GM engine recall

[Balsa]

GM recently posted an engine recall because their recommended oil weight of 0W-20 is too thin to adequately protect the engine. They changed their recommended oil weight to 0W-40. In short, heavier weight oil increases the thickness of the oil film on rod bearing reducing the risk of galling under high loads. The actual situation is more complicated. The Motor Oil Geek goes into more detail on Youtube.

So...Is the recommended 0W-20 the best oil choice for engine longevity or was the weight chosen to increase fuel economy?

Please post a response if you know the what the Tundra's owner's manual recommends for oil weight? - I assume that Tundra, with the same engine, would be considered a heavy duty application vs the GX.

What do the owner's manuals recommend for the GX in Australia or other international location? - Assuming that Australia does not have to comply with USA CAFE standards, so fuel economy would be less of a consideration in the oil weight recommendation.

Toyota's quality has always been better than GM, so I'm inclined to trust Toyota's oil weight recommendation, but I'd still like to know if there is any difference in recommendations in the various applications of this engine.

 

[A10MileHusker]

Here is some quick info I found online regarding US vs AU fluids.

US:

AU:

 

[Balsa]

Thanks A10MileHusker. I found the 2025 USA Tundra and 2025 Australia GX owners manuals. These both listed 0W-20 as the recommend oil. The note, "This viscosity prescription is for the USA market only; a wider range of viscosities is allowed for other markets." suggest that 0W-20 is the balance point of fuel efficiency and protection. The AU alternatives are only a 30 weight oil, so the alternative recommendations are not a major swings in viscosity.

 

[JoeRob]

Don't make any changes with the oil to your GX due to what GM is doing - that is a GM issue. Lexus/Toyota guarantees their engines based upon use of Toyota/Lexus oil. The owner's manual says that if any oil other than the recommended Toyota/Lexus brand, 0W-20 was put in - at the next scheduled oil change interval, drain the "other" brand of oil and put in Toyota/Lexus recommended oil.

 

[cmfhsu]

Agreed. The GM issue is specific to that one engine and not related to this engine in the GX. GM and Toyota have been running 0w20 oil for around 15 years now with great reliability. Also, I suspect the change in oil weight is really a cheap bandaid for GM so they don't have to do a massive recall like Toyota.

There are some reasons you might want to run heavier oil in your GX, but this is not one of those reasons.

 

[Bret_T]

I wonder if the US and AU engines are 100% identical or if there might be some internal differences that necessitate only using 0W-20 in the US engines.

 

[lowrange44]

This is a page from the Lexus Australia GX 550 manual. 0w-20 is still the preferred oil but others are listed as optional. Maybe due to operating temps, fuel economy standards or oil availability.

 

[JoeRob]

The GM motor recall is for the L87 engine, manufactured in Buffalo, N.Y. Over 600,000 have (maybe) a defect affecting the crankshaft and connecting rods. If the engine has the defect, there is a code created (how??) and if the code is found upon scanning the computer, the engine is "replaced entirely". Search the internet using 'L87' and you will get lots of info.
My apology for posting in this Lexus forum on this but the subject has been brought up so I searched and posted.

 

[Balsa]

@JoeRob the point of this thread is to know the range of oil specs for the V35A-FTS engine. All manufactures are specifying lighter weight oil in the USA in order to increase MPG ratings, include Toyota/Lexus. Toyota is pretty consistent with its 0W-20 recommendation for this engine, but the oil spec from Australia shows that higher weight oil is also within specs. Under normal operation, 0W-20 is the way to go. If operating with high torque needs, like frequent towing, a 30 weight oil may be a better choice. If operating in high temps, a 5W or 10W may be a better choice than 0W.

 

[cmfhsu]

I mean you basically nailed it, except the number in front of the W only matters at low temps, not in high temps (inb4 shear stability and base stock arguments).

And I'd bet quite a lot of money there's no internal differences between USA and Australia's engines. The US has quite strict emissions & economy regulations so manufacturers always spec thinner oil in the US than elsewhere.

 

[jclaffee]

Agreed. The GM issue is specific to that one engine and not related to this engine in the GX. GM and Toyota have been running 0w20 oil for around 15 years now with great reliability. Also, I suspect the change in oil weight is really a cheap bandaid for GM so they don't have to do a massive recall like Toyota.

They are doing a massive recall like Toyota.