Good low volatility 10w-30 for a Skyactive GDI engine?

Good to see this. I try to comment on every ND Miata post to encourage the owner to change the gear oil. Trans oil is a good idea too. Both the gearbox and final drive on these cars are proven to run quite hot. Frequent fluid changes on both should help them to survive longer.
These things really are street legal go-karts, built with an obsession on low weight, especially this generation. the rear diff has a capacity of 2/3 of a quart, the transmission only 2.2 quart, that's not much volume to dissipate heat into, it makes sense to use the best you can find,


Referring back to the OP (post#1)… There is specific viscosity called for in the Operator’s Manual quote. In my 2019 Miata Owners Manual same wording but for Mexico the specific viscosity was 5w-30. (now 10w-30) Then says if you cannot find 10w-30, put 5w-30 in. The 2019 OM says cannot find 5w-30 then 5w-20

That is specific viscosity recommendations for the same vehicle.

Climate is variable from desert, Puerto Rico to Canada and one viscosity recommended 0w-20.

The variable I have not heard is the fuel supplied.


So why did the viscosity requirements change for Mexico to 10w-30. Personally do not care but that should be a neon light that a decision was made with higher thinking than you or me. (or oil experts here) They are specific…


This has me wondering also, why did it move up? the trend for the last 2 decades has been thinner and thinner, the talk of availability got me wondering and i poked around the https://www.walmart.com.mx, 0w-20 is in fact MIA in Mexico, but 5w-30 is common as are most other weights, supertech is available, along with liquimolly motol etc, if the CAFE free ideal weight was still 0w-20 and it was not available 5w-30 would be a "next best thing" but they did not they went for 10w-30. Why? there are no engine changes for 2022, and other and an ABS modification
in the form of KPC there were no other changes to the entire car.
Post #3 here for a Miata. Notice all the different viscosities.

I can overthink this but the same vehicle around the world? Does this give the Miata owner to choose anything? Not my bag to overthink this, there is a reason these cars have the highest reliability.
I have seen that chart posted elsewhere and it is wild compared to the US chart with up to 50wt, see re-attached here again this motor is made in Japan for the world, only difference I know for Europe is a mandated stop/start system for engine off at stop lights.

As for the weather here I wish we rarely saw 90, we get a short 6-8 week but intense phoenix like summer, triple digit highs are common, the high last summer was 117f, low hundreds are more common same for the winter 6-8 weeks, sub zero temps, Not planning on being here for the next one.
 

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Per your attachment that show ambient temperature recommended viscosity notice that it all refers to cold ambient temp. not hot climate. My suggestion would be to stay with 0w-20. There are variables that are not discussed. And CAFE is only for USA. (Not Canada and Puerto Rico) My NC Miata took 5w-20… 20 weight oils been running great for 20 years.

I do not know for sure but Mexico Pemex fuel (Magna Sin) may possibly be the reason for the higher viscosity required.
 
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The winter rating differences between 10W and 5W is only -5°C (CCS of -25C vs. -30C and MRV of -30C vs. -35C)

i.e. 10W is safe to use in most US states and definitely southern states and Mexico type weather ... Check your winter temperature range to make sure.

I would use a good 10W-30 (e.g. M1 EP) over any 0W/5W-20 and even over 5W-30 if no need for the 5W winter protection. If you really need a 5W or 0W for winter protection, then you should get a block heater as well. Unless you buy 0W to get a fancy oil and not necessarily for winter or cold weather purposes ... for example some people buy 0W (e.g. 0W-40 Euro or 0W-30) to get a better base oil not because they live in Alaska or Canada. I've bought a few M1 FS Euro 0W-40 and Castrol a3/b4 0W-40. I think if I buy it again it will be the M1. A little suspicious of the Castrol 0W-40 but that's another story.

Having said that, follow your owner's manual recommendation :)
 
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Per your attachment that show ambient temperature recommended viscosity notice that it all refers to cold ambient temp. not hot climate. My suggestion would be to stay with 0w-20. There are variables that are not discussed. And CAFE is only for USA. (Not Canada and Puerto Rico) My NC Miata took 5w-20… 20 weight oils been running great for 20 years.

I do not know for sure but Mexico Pemex fuel (Magna Sin) may possibly be the reason for the higher viscosity required.
Puerto Rico is a US territory federal law applies there, Canada's regulations are harmonized with the US to make a unified automotive market

Canada sets GHG emissions limits for new light-duty vehicles under the Passenger Automobile and Light Truck Greenhouse Gas Emission Regulations. The most recent amendments, adopted in 2014, require a 5% annual reduction in CO2-equivalent per mile for passenger cars from 2017 to 2025. New fleet average GHG limits for light trucks tighten 3.5% per year from 2017 to 2021 and 5% per year from 2022 to 2025. These standards are closely aligned with the United States.
https://www.transportpolicy.net/standard/canada-light-duty-fuel-consumption-and-ghg/
 
Puerto Rico is a US territory federal law applies there, Canada's regulations are harmonized with the US to make a unified automotive market

https://www.transportpolicy.net/standard/canada-light-duty-fuel-consumption-and-ghg/
So in 2011 CAFE… You have to look at when the 20 weight oils started. Honda first came out 2002. Many companies followed. Way before CAFE But that is good info… Thanks for the link.

Here is the oil recommendation from LiquiMoly for a 2004-2005 NB Miata.
The present ND Miata ships with Idemitsu’s 0w-20 from the factory around the world.
 
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So in 2011 CAFE… You have to look at when the 20 weight oils started. Honda first came out 2002. Many companies followed. Way before CAFE But that is good info… Thanks for the link.

Here is the oil recommendation from LiquiMoly for a 2004-2005 NB Miata.


CAFE started in 1975.
 
Oops and thanks. This is not a thick or thin discussion cause all these oils work. So why does Mexico have 10w-30 recommended? (very specific)


To be honest, this is the first I’ve heard of this. I have only read about 0w-20 and 5w-30 for the SkyActiv motors, the latter due to lack of availability in some parts of the world. I don’t think that is much of a issue these days.
 
This morning I ordered Redline MT-90 for the transmission and 75-90 for the rear diff, I like and have used redlines gear oils, I have never tried thier engine oil, never could quite choke down the price but this MX-5 has a small crankcase, and my commute is short. I should look into that as well.
I agree with your choice of Redline for trans and diff but their engine oils are on the thick side if you are going with the high performance line. Going back to you saying "precious little ponies to squander" maybe a thinner 5w30 say PUP or PP. Boutique wise, perhaps Amsoil SS 5w30 is a good bit thinner than the Redline.
 
Oops and thanks. This is not a thick or thin discussion cause all these oils work. So why does Mexico have 10w-30 recommended? (very specific)
As I said earlier, it's likely due to the availability of poorer quality (high VII percentage, crap quality) 5w-30's. A 10w-30 is typically going to be more shear resistant. This is an easier way to guarantee a more robust oil without going to the trouble of coming up with your own oil approval. This is why the S2000 spec'd 10w-30 for example.
 
As I said earlier, it's likely due to the availability of poorer quality (high VII percentage, crap quality) 5w-30's. A 10w-30 is typically going to be more shear resistant. This is an easier way to guarantee a more robust oil without going to the trouble of coming up with your own oil approval. This is why the S2000 spec'd 10w-30 for example.
In 2022 the Operator’s Manual changed it’s requirement for the viscosity from 5w-30 to 10w-30 for the ND Miata for Mexico… So why did they change it?
It’s OK not to answer if you do not know the answer…. By the way it would be more shear resistant. VII polymer strings have a temporary viscosity reduction at the MOFT location of bearing but why the engineers changed the OM for 2022?
 
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I have a 2022 Mazda MX-5 on the way, this year for Mexico the recommended weight moved from 5w-30 to 10w-30 for temps of 0f and above, the US 0w-20 is not recommended.
You are overthinking and misinterpreting things. In Mexico, synthetic 0W-20 is hardly available, and they recommend conventional 5W-30 or 10W-30 with shorter oil changes. Moreover, there is no temperature below 0 ºF in Mexico. Synthetic 0W-20 with longer oil changes is approved for all across the world, including Mexico. There is no reason for you to use conventional oil and do shorter oil changes with your car—in fact, this is simply a bad idea unless, unlike people in Mexico, you have easy and cheap access to synthetic oil. In Mexico, Group I oils are still very common and popular, while they no longer exist in the US.
 
You are overthinking and misinterpreting things. In Mexico, synthetic 0W-20 is hardly available, and they recommend conventional 5W-30 or 10W-30 with shorter oil changes. Moreover, there is no temperature below 0 ºF in Mexico. Synthetic 0W-20 with longer oil changes is approved for all across the world, including Mexico. There is no reason for you to use conventional oil and do shorter oil changes with your car—in fact, this is simply a bad idea unless, unlike people in Mexico, you have easy and cheap access to synthetic oil. In Mexico, Group I oils are still very common and popular, while they no longer exist in the US.
Here I was thinking we had a free trade agreement with Mexico?
 
In 2022 the Operator’s Manual changed it’s requirement for the viscosity from 5w-30 to 10w-30 for the ND Miata for Mexico… So why did they change it?
It’s OK not to answer if you do not know the answer…. By the way it would be more shear resistant. VII polymer strings have a temporary viscosity reduction at the MOFT location of bearing but why the engineers changed the OM for 2022?
Sorry, you are going to have to clarify your statement, which are you claiming is more shear resistant?

And yes Bill, I'm aware of the change in the requirement, that's what my statement was referencing. They may have observed some less than desirable performance characteristics from the 5w-30's commonly available in Mexico (such as significant viscosity loss due to the use of cheap VII polymer and very thin bases) and so they've "upgraded" the spec to 10w-30, which will be more shear stable due to the use of higher viscosity base oils.
 
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