An engine can be designed to tolerate a lower grade but there’s nothing that would prevent the use of a higher one. The oil cooler you mention wouldn’t get in the way of a 30-grade.
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,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.
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…
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.Post #3 here for a Miata. Notice all the different viscosities.
Manual says 0w20 in the USA - MX-5 Miata Forum
Manual says 0w20 in the USA ND Maintenanceforum.miata.net
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.
Puerto Rico is a US territory federal law applies there, Canada's regulations are harmonized with the US to make a unified automotive marketPer 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.
https://www.transportpolicy.net/standard/canada-light-duty-fuel-consumption-and-ghg/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.
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.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.
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Oil guide
When it comes to the question: "Which engine oil?" or "Which transmission oil?", the LIQUI MOLY Oil Guide has the answer.www.liqui-moly.com
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)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)
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.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.
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.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)
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?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.
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.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.
Here I was thinking we had a free trade agreement with Mexico?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.
My understanding was/is? going to move to a climate about the same as Mexico…But he is not in Mexico nor is he going to Mexico.
My understanding was/is? going to move to a climate about the same as Mexico…
Sorry, you are going to have to clarify your statement, which are you claiming is more shear resistant?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?