Oil Weight for SkyActiv 2.5 L

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Buddywh2

Member
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2011 M3 Touring / 2014 CX-5 Touring
I noticed the manual indicates that only in North America (USA) is the 0w20 oil spec'd... it's 5w30 in place pretty much everywhere else in the world. Does anyone know if there's any differences in the engine that would warrant this?

I'd really prefer to use the 5w30 oil and I believe the 0w20 is only spec'd because Mazda's trying to pump up their CAFE fleet fuel economy numbers. I don't think 0w20 contributes that much economy to an individual vehicle (maybe a couple tenths of mpg). It only makes a difference across a huge fleet of vehicles so it's much more important to Mazda than me.
 
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Yep, it's specced for fuel economy and better cold protection. A majority of engine wear happens at cold start, when most of the oil has drained to be pan. A lower weight oil, will flow faster to those 'starved' locations to reduce engine wear.

If you prefer to run 5w-30, that is up to you. I can't find it now, but running 0w-30 over 5w-30 increases fuel economy by 1-2% in a laboratory setting.
 
inlinev said:
Yep, it's specced for fuel economy and better cold protection. A majority of engine wear happens at cold start, when most of the oil has drained to be pan. A lower weight oil, will flow faster to those 'starved' locations to reduce engine wear.

If you prefer to run 5w-30, that is up to you. I can't find it now, but running 0w-30 over 5w-30 increases fuel economy by 1-2% in a laboratory setting.
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How? Most 0-30 is thicker than 5-30 both cold, and at 100*C.

People don't much understand oil thickness, I've found.

That said, Mazda says put 0-20 in it, and I'll put 0-20 in it. Why? Because I doubt it matters a hill of beans, and this way my warranty is in just that much less jeopardy for the next 70K miles.
 
There is no difference in engines that require some Mazda engines to use 0w20 and others to use 5w30. 0w20 is only spec'd for USA & Canada while Mexico uses 5w30. That being said, either will work just fine here in FL but, I will be using 0/5w30 in my 2014 2.5 CX5. Ed
 
Unobtanium said:
How? Most 0-30 is thicker than 5-30 both cold, and at 100*C.

People don't much understand oil thickness, I've found.

That said, Mazda says put 0-20 in it, and I'll put 0-20 in it. Why? Because I doubt it matters a hill of beans, and this way my warranty is in just that much less jeopardy for the next 70K miles.
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Here it is. See fine print.

https://mobiloil.com/en/motor-oils/mobil-1/mobil-1-advanced-fuel-economy

0w oil is thinner than 5w oil when cold. 0 weight has a lower viscosity.
 
inlinev said:
Here it is. See fine print.

https://mobiloil.com/en/motor-oils/mobil-1/mobil-1-advanced-fuel-economy

0w oil is thinner than 5w oil when cold. 0 weight has a lower viscosity.
Click to expand...

Thanks for the link. As I thought, their 0-30 is thicker at 40 (cold) and 100 (operating temp ) Celsius than their 5-30. Like I said, most people don't understand oil viscosity very thorouthly, and it's poorly marketed. Here is the 5-30 for your comparison.

https://mobiloil.com/en/motor-oils/mobil-1/mobil-1-extended-performance#5W-30
 
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inlinev said:
Yep, it's specced for fuel economy and better cold protection. A majority of engine wear happens at cold start, when most of the oil has drained to be pan. A lower weight oil, will flow faster to those 'starved' locations to reduce engine wear.

If you prefer to run 5w-30, that is up to you. I can't find it now, but running 0w-30 over 5w-30 increases fuel economy by 1-2% in a laboratory setting.
Click to expand...

It gets colder in the US than it does in Northern Europe?
 
Buddywh2 said:
I noticed the manual indicates that only in North America (USA) is the 0w20 oil spec'd... it's 5w30 in place pretty much everywhere else in the world. Does anyone know if there's any differences in the engine that would warrant this?

I'd really prefer to use the 5w30 oil and I believe the 0w20 is only spec'd because Mazda's trying to pump up their CAFE fleet fuel economy numbers. I don't think 0w20 contributes that much economy to an individual vehicle (maybe a couple tenths of mpg). It only makes a difference across a huge fleet of vehicles so it's much more important to Mazda than me.
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I'm sticking to the 0W20 oil that's recommended by Mazda for use in the usa.

where did you get the idea that 5W30 is spec pretty much everywhere else?
Sure, mexico recommends 5W30 because it never gets cold there, but it looks to me like both 0W20 and 5W30 provide adequate protection even at high temperatures.
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srource:
http://idn.tweddle.com/media/mazda/81a9d_CX-5_8DV5-EE-14L-R_Edition1_web_OM_LR.pdf
 
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The standard calculation weight for oil is 7.5lb per gallon/1.95lb per liter. Gotta do that weight and balance!
 
40 degrees C is not the temp of concern for cold start viscosity performance. When cold, a 0W will flow faster than a 5W. The colder you get, the bigger the difference. When very cold, the oil has to let the engine "crank" first, then it has to be able to be pumped. Both cranking and pumping performance are measured at very cold temps to classify the XW part of the viscosity.

At "operating" temp, a 30 has more resistance to flow vs a 20. A 20 gets slightly better fuel economy, without sacrificing wear protection when its use is ok'd. Every little bit helps!

Some countries may not have the latest oil viscosities available. The quality of lubes may vary more as well. A historically more common thicker viscosity oil may be a) available, and b) provide more of a safety factor if an oil blender cuts corners.
 
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I agree engine starts causes the most engine wear if all else is sound.

Also the lighter 20 also runs cooler then 30 because of better flow/circulation. The problem with 20 is in very hot weather the oil will get a little too thin and doesn't meet the OEM specs (High Temperature Shearing) for proper engine protection as you live closer to the Equator like Mexico, therefore 30 weight is recommended.

(Don't jump all over me because I used Amsoil just as a comparison for a wide range of oil grades on one chart). For example looking at Amsoil'd spec sheet on oils from 0W20 to 5W50 you can see the High-Temperature (150C) & High-Sear Tests the heavy oils offer better protection. Here's a brochure that shows the specs as a comparison..
http://www.amsoil.com/lit/databulletins/g2880.pdf

But anyone planning to change oil grades should 1st use the OEM's recommended grade of oil and do an oil analysis as a reference and testing other grades to make sure engine metal wear is not increased.
 
First oil change I did I went with 5w20 because the store was out of 0w20. Haven't noticed a difference in performance and I do not feel as if the 0w20 would have been a better choice.
 
russiankid said:
First oil change I did I went with 5w20 because the store was out of 0w20. Haven't noticed a difference in performance and I do not feel as if the 0w20 would have been a better choice.
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Do you recall what brand/product oil you used? The Mazda GF-5 with Moly oil is some really really slick stuff. I plan on switching from the dealership's bulk 0w20 Castrol oil which is nowhere near as thin. For daily driving I think a 5-quart container of 0w20 Pennzoil Platinum Full Synthetic could be had at around $23 at walmart and presents the best bang for buck. At around $10-12 per quart the 0w20 Mazda is the best daily driving oil to get but will cost you more. The Amsoil is best for track applications for its high heat performance imho.

**Lower is Better**

Product Brand Name Viscosity Kinematic Viscosity at 40 degrees C (cSt) Kinematic Viscosity at 100 degrees C (cSt)
Amsoil Signature Series 0W-20 47.3 8.7
Mazda GF-5 with Moly 0W-20 35.0 8.3
Mobil1 Advanced Fuel Economy 0W-20 44.8 8.7
Pennzoil Platinum Full Synthetic 0W-20 42.8 8.4
 
Castrol Edge is what I used. Cost is not a huge factor for me for things like oil. I usually run either Castrol or Mobile in all of my vehicles and have never had a problem.
 
Lbear said:
Is MedCenterMazda a good place to get OEM Mazda Moly Oil and OEM oil filters?
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Yes. But they raised price recently and also raised the free-shipping threshold from $100 to $150. Some people had a hard time to find the oil change kit with moly oil from their updated website.
 
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