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

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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. here in the high dessert we get 115f summers and by next winter I should have moved south to basically Mexico weather. Going to start it on a diet of 10w-30 and stick with it for the forseeable future. I guess these days 10w-30 is considered "Thicc"

Obviously I am looking for low wear and engine cleanliness but additionally The 2.0l Skyactive G is a GDI engine with no fuel washing the backs of the intake valves. examinations of in service engines has shown that deposits do accumulate on the intake valves, there is healthy debate about weather these deposits will eventally cause drivability issues or weather they reach a stable state and stop accumulating, but either way lower the volitility of the oil the batter,

Many seam to like Molly in these engines, but both of the recommended sources with high molly, Idemitsu and Toyota motor guard, have poor NOACK ratings so a bit contradictory.

I ran Mobil one for a long time, recently I have been using PUP, both have worked well for me in UOA's in other motors. I tend to stick with mainstream oils but would consider a harder to source boutique oil if there was a solid reason to go to it.


One oddity about 10w-30 weights is across several brands they don't seam to get many approvals other than some ancient domestic specifications, is this just because of the viscosity? or is there something more to this? in this aplication no specific approvals are required other than the obvious:

Mexico:
Use API SM or higher SAE 10W-30 engine oil. If SAE 10W-30 engine oil is not available, use SAE 5W-30, 0W-30 or 5W-20 engine oil. The quality designation SM, SN or SP must be on the label.

US:
Only use SAE 0W-20 oil “Certified For Gasoline Engines” by the American Petroleum Institute (API). Oil with this trademark symbol conforms to the current engine and emission system protection standards and fuel economy requirements of the International Lubricant Standardization and Approval Committee (ILSAC), comprised of U.S. and Japanese automobile manufacturers.

▼ Recommended Oil U.S.A., Canada, and Puerto Rico Use SAE 0W-20 engine oil. Mazda Genuine Oil is used in your Mazda vehicle. Mazda Genuine 0W-20 Oil is required to achieve optimum fuel economy. For maintenance service, Mazda recommends Genuine Mazda Parts and Genuine Mazda Premium Oil.
 
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Redline or possibly our sponsors Performance Oil as they have a 10-30 as well. there are cheeper choices as well, BUT not as good!
 
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That Operator’s Manual is from North American Mazda. The Canada, US and Puerto Rico label API currently is SP (ILSAC GF-6) but in 2019 was SN highest and recommended. I do not know why they recommend now the 10w-30 for Mexico. They had 5w-30 recommended for my 2019 Miata in Mexico. Maybe the Pemex fuel has something to do with it, but just a suggestion. Octane actually decreases the explosive nature of fuel. Moly is a good thing but the Mazda oil has a Noack of 14 and is expensive. Focus on the word “recommends” with the after thought Mazda oil is required for optimum “fuel economy”. Required is not Mazda’s oil though. My Miata OM also recommended Castrol oil but did not discuss which product to use. Kinda leads you to believe that Castrol paid Mazda for the recommendation.

Mazda has a different formulation of oil in Europe made by Total and branded Mazda, do not know much about that oil.
 
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Noack has nothing to directly do with GDI deposits, as vaporized oil can't deposit anywhere. Only liquid oil, such as PCV oil mist, can cause deposits. High ash content and low-quality base oil increase the deposits. Do some research on BITOG. Lower Noack can indicate higher base-oil quality, but going to 10W-30 doesn't help because the Noack is only lower because the base oil is thicker. Moreover, thinner base oils have higher solvency (lower aniline point) than thicker base oils and will reduce the deposits. For that reason, a 5W-30 will actually result in less GDI valve deposits than a 10W-30, in complete contrast to what your intuition is telling you.
 
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I had a 2019 miata with the same engine. Stick with a good 0w20 like M1 EP. I used a thick euro 5w30 M1 ESP and the engine didn't seem to like it. It's a high revving quick throttle response engine and the thick 5w30 didnt help. These engines perform excellently with a 0w20 oil even with the revs up there.
 
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Noack has nothing to directly do with GDI deposits, as vaporized oil can't deposit anywhere. Only liquid oil, such as PCV oil mist, can cause deposits. High ash content and low-quality base oil increase the deposits. Do some research on BITOG. Lower Noack can indicate higher base-oil quality, but going to 10W-30 doesn't help because the Noack is only lower because the base oil is thicker. Moreover, thinner base oils have higher solvency (lower aniline point) than thicker base oils and will reduce the deposits. For that reason, a 5W-30 will actually result in less GDI valve deposits than a 10W-30, in complete contrast to what your intuition is telling you.
I can agree with you but it does point to other things like what the base oil is made of which also leads to how much polymer VII is in the oil. And I did run TGMO 0w-20 from your recommendation. I used a bore scope to look at the intake valves. My next oil will be PUP 0w-20, would not hurt IMO…

I do appreciate your input here. Just trying something new
 

RavenTai

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I had a 2019 miata with the same engine. Stick with a good 0w20 like M1 EP. I used a thick euro 5w30 M1 ESP and the engine didn't seem to like it. It's a high revving quick throttle response engine and the thick 5w30 didnt help. These engines perform excellently with a 0w20 oil even with the revs up there.
hmmm, I am aware there is minor loss in both power and effeciency with thicker oils. For 20 years I have been driving various Toyotas, inline 6's, and for the last decade Toyota v8's, none of them showed apparent power changes or measurable MPG change with oil selection, parasitic drag is just below the noise floor on these vehicles.

I ordered dozen Mazda oil filters for the Miata, when the small box showed up I was like surely there has been a mistake, I was shocked to find not only all 12 filters inside the tiny box but also quite a few pillow packs to fill the empt space, the oil filter is larger than a shot glass but not by much. perhase this is a different beast. this will actually be the first 4 banger I have owned, the high revving & broad power band is what makes this one fun, but there are precious few ponies to squander. that is an angle I had not considered
 

RavenTai

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Noack has nothing to directly do with GDI deposits, as vaporized oil can't deposit anywhere. Only liquid oil, such as PCV oil mist, can cause deposits. High ash content and low-quality base oil increase the deposits. Do some research on BITOG. Lower Noack can indicate higher base-oil quality, but going to 10W-30 doesn't help because the Noack is only lower because the base oil is thicker. Moreover, thinner base oils have higher solvency (lower aniline point) than thicker base oils and will reduce the deposits. For that reason, a 5W-30 will actually result in less GDI valve deposits than a 10W-30, in complete contrast to what your intuition is telling you.
I have some reading to do.
 
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hmmm, I am aware there is minor loss in both power and effeciency with thicker oils. For 20 years I have been driving various Toyotas, inline 6's, and for the last decade Toyota v8's, none of them showed apparent power changes or measurable MPG change with oil selection, parasitic drag is just below the noise floor on these vehicles.

I ordered dozen Mazda oil filters for the Miata, when the small box showed up I was like surely there has been a mistake, I was shocked to find not only all 12 filters inside the tiny box but also quite a few pillow packs to fill the empt space, the oil filter is larger than a shot glass but not by much. perhase this is a different beast. this will actually be the first 4 banger I have owned, the high revving & broad power band is what makes this one fun, but there are precious few ponies to squander. that is an angle I had not considered
I have an oil analysis somewhere in the section using M1 0w20 EP. I drove the car pretty hard bounced off the rev limited alot. Unless you're tracking the car, there's no need to consider 5w30. There was a noticeable difference in engine responsiveness with the euro 5w30. I'd advise against ir. Perhaps it's because I didn't track the car. The Mazda oil filters are ok but nothing to write home about. The build quality is good. I used them and mobil 1 with no problem. I miss that car dearly but I just couldn't fit right in it. I couldn't get comfortable because my ideal comfort was in between notches of the seat rail. One position was too close, tiring me when releasing the clutch, the other was comforrable but too far from the clutch. I miss the car dearly, perhaps one day I'll pick one up again.
 

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hmmm, I am aware there is minor loss in both power and effeciency with thicker oils. For 20 years I have been driving various Toyotas, inline 6's, and for the last decade Toyota v8's, none of them showed apparent power changes or measurable MPG change with oil selection, parasitic drag is just below the noise floor on these vehicles.

I ordered dozen Mazda oil filters for the Miata, when the small box showed up I was like surely there has been a mistake, I was shocked to find not only all 12 filters inside the tiny box but also quite a few pillow packs to fill the empt space, the oil filter is larger than a shot glass but not by much. perhase this is a different beast. this will actually be the first 4 banger I have owned, the high revving & broad power band is what makes this one fun, but there are precious few ponies to squander. that is an angle I had not considered
Oil temps are less with the thinner oils. The pistons have squirters to target piston cooling and cylinder lubing.
 

RavenTai

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Redline 10w-30 has a HTHS of 3.5 and a NOACK of 6
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.
 

RavenTai

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Oil temps are less with the thinner oils. The pistons have squirters to target piston cooling and cylinder lubing.
I did not know that this one has oil squirters, My land cruiser had them, it was part of that motors longevity.
 
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I did not know that this one has oil squirters, My land cruiser had them, it was part of that motors longevity.
Oil jets…

The valve timing is adjusted with hydraulic oil pressure to achieve the high compression. The control sensor is a thermal ion circuit using the spark plug electrodes.
 
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Oil temps are less with the thinner oils. The pistons have squirters to target piston cooling and cylinder lubing.

Is this a known fact? I would expect the most minimal of oil temperature differences between a 5w-30 and a 0w-20, if any. The specific heat capacities of those two grades will be for all intents and purposes identical. I suppose you can make the case there will be ever so slightly more hydrodynamic drag, but as a source of heat that's nothing compared to what's being generated by burning all that fuel.
 
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Is this a known fact? I would expect the most minimal of oil temperature differences between a 5w-30 and a 0w-20, if any. The specific heat capacities of those two grades will be for all intents and purposes identical. I suppose you can make the case there will be ever so slightly more hydrodynamic drag, but as a source of heat that's nothing compared to what's being generated by burning all that fuel.
Oil temperature is not monitored on stock but Miata’s are tracked a lot and that oil temperature is closely watched. 30% of the heat is exchanged by oil, and the flow of oil. Tracked cars can see oil temperature decrease.

So… not ot say this is true but oil flow is engine cooling and temperature is always changing the viscosity. Target coolant temperature is close to oil temperature on street but tracked cars have much higher oil temperatures than coolant. Some guys run 0w-20 to get the benefits. Others run 0w-30 or 5w-30.

 
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