Castrol Edge Euro 5W-30 vs. 5W-40

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Both these grades of Castrol Euro are readily available at Walmart (and at the same price), so I was curious as to the actual differences between the two.

I understand they both meet the minimum performance specs necessary to have the various Euro manufacturer's approvals, and that, with the minimum HTHS set by those approvals, there is often little functional difference between 30 and 40 grade Euro oil.

As far as approvals on the bottle, the differences are:

--SL (5W-30) vs SP (5W-40) API ratings, which I speculate are based on the API/EPA rules for rating 30 vs 40 grade oils and does not represent any real difference.

--The 5W-40 has A40 and RN ratings that the 5W-30 does not have, which I also speculate might be a reflection of simply a requirement of a 40 grade (rather than strictly performance requirement) needed for those approvals.


Walmart, who are generally known to consolidate their offerings, carries both grades at the same price, so I was wondering how different they really are. So:

--Are my speculations above valid that the Porche, Renault and API rating differences mostly reflect a 40-grade requirement for those approvals (even if a 30-grade had roughly all the same performance specs)?

--Any significant difference in HTHS between these two Castrol grades?

--Both will meet the stay-in-grade Euro spec, but is there any significant shear-stability increase in the narrower-range 5W-30?

--Any other significant difference that might cause one to choose one or the other off the shelf?

--Any idea why Walmart carries both?

Thanks!
 
Both these grades of Castrol Euro are readily available at Walmart (and at the same price), so I was curious as to the actual differences between the two.

I understand they both meet the minimum performance specs necessary to have the various Euro manufacturer's approvals, and that, with the minimum HTHS set by those approvals, there is often little functional difference between 30 and 40 grade Euro oil.

As far as approvals on the bottle, the differences are:

--SL (5W-30) vs SP (5W-40) API ratings, which I speculate are based on the API/EPA rules for rating 30 vs 40 grade oils and does not represent any real difference.

--The 5W-40 has A40 and RN ratings that the 5W-30 does not have, which I also speculate might be a reflection of simply a requirement of a 40 grade (rather than strictly performance requirement) needed for those approvals.


Walmart, who are generally known to consolidate their offerings, carries both grades at the same price, so I was wondering how different they really are. So:

--Are my speculations above valid that the Porche, Renault and API rating differences mostly reflect a 40-grade requirement for those approvals (even if a 30-grade had roughly all the same performance specs)?

--Any significant difference in HTHS between these two Castrol grades?

--Both will meet the stay-in-grade Euro spec, but is there any significant shear-stability increase in the narrower-range 5W-30?

--Any other significant difference that might cause one to choose one or the other off the shelf?

--Any idea why Walmart carries both?

Thanks!
They are both 2nd tier Castrol offerings (1st: 0W30/40). 5W40 has HTHS 3.64, which is nothing impressive. 5W30 is 3.5. Only difference is that 5W30 will be bit more stable and has lower Noack. However, in the end of OCI, you will still end up in 11’ with both oils.
The thing to do is grab Mobil1 0W40 that is being sold next to them.
 
Wal-Mart carries them both to sell to the respective OEM requirements/Approvals/License customers. The 5w-30 SL does not meet any Porsche specifications so no it will not be equivalent. Close? maybe. 5w-30 may be more shear stable but it doesn't mean it will maintain it better or equal to a 5w-40. If you're looking for a robust Euro oil the 5w-40 has more standards & probably for good reason. VI are virtually the same 165 vs 170.

5w-30 Meets or exceeds industry standards:​

  • ACEA A3/B4
  • API SL
  • BMW Longlife-01
  • MB-Approval 229.5
  • VW 502 00 / 505 00

5w-40 Meets or exceeds industry standards:​

  • ACEA A3/B4
  • API SP
  • BMW Longlife-01
  • MB-Approval 229.3/229.5
  • MB 226.5 SFU
  • RN 0700 / RN 0710
  • VW 502 00/505 00
  • Porsche A40
  • Chrysler MS-12991
 
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Wal-Mart carries them both to sell to the respective OEM requirements/Approvals/License customers. The 5w-30 SL does not meet any Porsche specifications so no it will not be equivalent. Close? maybe. 5w-30 may be more shear stable but it doesn't mean it will maintain it better or equal to a 5w-40. If you're looking for a robust Euro oil the 5w-40 has more standards & probably for good reason.

5w-30 Meets or exceeds industry standards:​

  • ACEA A3/B4
  • API SL
  • BMW Longlife-01
  • MB-Approval 229.5
  • VW 502 00 / 505 00

5w-40 Meets or exceeds industry standards:​

  • ACEA A3/B4
  • API SP
  • BMW Longlife-01
  • MB-Approval 229.3/229.5
  • MB 226.5 SFU
  • RN 0700 / RN 0710
  • VW 502 00/505 00
  • Porsche A40
  • Chrysler MS-12991
There is no good reason. Porsche doesn’t have full-SAPS approval in W30 grade. It is only A40, that limits it to W40.
Both have same add pack, API SP. 5W30 cannot be SP bcs. phosphorus levels, which is too high for anything API SM or newer in 30 grade.
RN and Chrysler are also W40. And really not stringent.
 

Thanks for the page!

They are both 2nd tier Castrol offerings (1st: 0W30/40). 5W40 has HTHS 3.64, which is nothing impressive. 5W30 is 3.5. Only difference is that 5W30 will be bit more stable and has lower Noack. However, in the end of OCI, you will still end up in 11’ with both oils.
The thing to do is grab Mobil1 0W40 that is being sold next to them.

Thank you for that information-- very helpful. I don't disagree at all with your point that the M1 0W-40 is the better oil, but the 5W's that are the subject of my question are more than adequate for all my old, low-tech applications that are never raced or run hot.

So, given my current financial situation (retired early, saving every penny until I qualify for SS), I'm using the Castrol because I can find it cheap.

Since for my applications the Super Tech 5W-30 SP would likely be perfectly adequate, I think the Euro 5W's from Castrol will be more than adequate to handle the 10K OCI's I plan to use-- little need for me to spend more for the additional quality of the M1.


Wal-Mart carries them both to sell to the respective OEM requirements/Approvals/License customers. The 5w-30 SL does not meet any Porsche specifications so no it will not be equivalent. Close? maybe. 5w-30 may be more shear stable but it doesn't mean it will maintain it better or equal to a 5w-40. If you're looking for a robust Euro oil the 5w-40 has more standards & probably for good reason. VI are virtually the same 165 vs 170.

5w-30 Meets or exceeds industry standards:​

  • ACEA A3/B4
  • API SL
  • BMW Longlife-01
  • MB-Approval 229.5
  • VW 502 00 / 505 00

5w-40 Meets or exceeds industry standards:​

  • ACEA A3/B4
  • API SP
  • BMW Longlife-01
  • MB-Approval 229.3/229.5
  • MB 226.5 SFU
  • RN 0700 / RN 0710
  • VW 502 00/505 00
  • Porsche A40
  • Chrysler MS-12991

Your contention that the extra approvals indicate more robust oil is reasonable on its face, but I had a suspicion that those differences were based more on approval rules allowed for various grades rather than actual performance, and edyvw seems to have confirmed that below.


There is no good reason. Porsche doesn’t have full-SAPS approval in W30 grade. It is only A40, that limits it to W40.
Both have same add pack, API SP. 5W30 cannot be SP bcs. phosphorus levels, which is too high for anything API SM or newer in 30 grade.
RN and Chrysler are also W40. And really not stringent.

Thanks again for this additional information. It sounds like for me (who's only looking for a moderately stout daily driver-type oil for 10K OCI's) there is no significant functional difference between these two 5W Castrol Euro oils.

If I understand your first response correctly, the 5W-40 will be marginally stouter than the 5W-30, but also marginally less stable than the 5W-30, so by the end of the OCI (10K for me), one basically has the same oil.

Assuming that understanding is correct, I will conclude that (for me) there is no difference between these two Castrol Euro grades and will use either.

Still curious as to why Walmart-- generally an aggressive consolidator that doesn't like to carry overlapping stock-- carries both of these oils in-store.

Prices are the same, so I can't even explain it via price discrimination theory.

Kind of a mystery to me, but you guys have answered the question for my specific applications, so I guess I'll just let the mystery remain.

Thanks much for the help, and happy holidays to you all!
 
Your contention that the extra approvals indicate more robust oil is reasonable on its face, but I had a suspicion that those differences were based more on approval rules allowed for various grades rather than actual performance, and edyvw seems to have confirmed that below.

Yes there are rules that allow certain industry standards. Biggest thing for me anyways is the long standing argument that closer multi grades shear less so let's just go with a lower viscosity grade falls flat when extending intervals. Diesel forums I read often say start with a 10w-30 because a 5w-40 sheers more. I just disagree with that and starting with a higher grade can still end up being higher viscosity bey the end run. It all depends on the application I suppose though. It's all fun to dig into isn't it. 😀
 
Yes there are rules that allow certain industry standards. Biggest thing for me anyways is the long standing argument that closer multi grades shear less so let's just go with a lower viscosity grade falls flat when extending intervals. Diesel forums I read often say start with a 10w-30 because a 5w-40 sheers more. I just disagree with that and starting with a higher grade can still end up being higher viscosity bey the end run. It all depends on the application I suppose though.

Yeah, my understanding (and you probably already know this) is that one cannot simply assume that because a multi-viscosity oil is low range that it will also be less prone to shear.

Since it's possible to create an oil with low-range viscosity by using lower-quality base oils and cheap VIIs, it's also possible that that low-range oil will have the same (or even higher) shear rate as a higher range oil that was made with a better base and higher quality VIIs.

Because of all these varying parameters, it seems one can never make any assumptions about shear based only on the grade range-- thus my question here.

edyvw confirms that, in the case of the Castrol 5W-30 vs 5W-40, the lower range 5W-30 actually is a bit more stable.



It's all fun to dig into isn't it. 😀


It really is!
 
Thanks for the page!



Thank you for that information-- very helpful. I don't disagree at all with your point that the M1 0W-40 is the better oil, but the 5W's that are the subject of my question are more than adequate for all my old, low-tech applications that are never raced or run hot.

So, given my current financial situation (retired early, saving every penny until I qualify for SS), I'm using the Castrol because I can find it cheap.

Since for my applications the Super Tech 5W-30 SP would likely be perfectly adequate, I think the Euro 5W's from Castrol will be more than adequate to handle the 10K OCI's I plan to use-- little need for me to spend more for the additional quality of the M1.




Your contention that the extra approvals indicate more robust oil is reasonable on its face, but I had a suspicion that those differences were based more on approval rules allowed for various grades rather than actual performance, and edyvw seems to have confirmed that below.




Thanks again for this additional information. It sounds like for me (who's only looking for a moderately stout daily driver-type oil for 10K OCI's) there is no significant functional difference between these two 5W Castrol Euro oils.

If I understand your first response correctly, the 5W-40 will be marginally stouter than the 5W-30, but also marginally less stable than the 5W-30, so by the end of the OCI (10K for me), one basically has the same oil.

Assuming that understanding is correct, I will conclude that (for me) there is no difference between these two Castrol Euro grades and will use either.

Still curious as to why Walmart-- generally an aggressive consolidator that doesn't like to carry overlapping stock-- carries both of these oils in-store.

Prices are the same, so I can't even explain it via price discrimination theory.

Kind of a mystery to me, but you guys have answered the question for my specific applications, so I guess I'll just let the mystery remain.

Thanks much for the help, and happy holidays to you all!
Use any. If I had to choose between two, I would go 5W30.
Porsche A40 is not stringent approval per se. What you want to pay attention is MB229.5. Both have it.
 
Use any. If I had to choose between two, I would go 5W30.
Porsche A40 is not stringent approval per se. What you want to pay attention is MB229.5. Both have it.

Perfect-- my intuition was to go with the 5W-30, so thanks for that confirmation.

Really appreciate your help on this!
 
If Mobil 1 FS 5w-40 is the same price as the two Castrol products mentioned above, would that be a higher quality oil or is it just on par? Thanks.
 
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The 5w-30 may not be safe for lspi prone engines with its 2800 ppm of calcium and no mag. The SP 5w-40 is more balanced. Prior one also had 2800ppm.

Credit goes to Himemsys

 
It is still irrelevant. Both oils have the same additive pack.
It would be IF OP was looking for a Porsche specification, which they are not, there is none on the 30 grade.

5w-30 Meets or exceeds industry standards:​

  • ACEA A3/B4
  • API SL
  • BMW Longlife-01
  • MB-Approval 229.5
  • VW 502 00 / 505 00

5w-40 Meets or exceeds industry standards:​

  • ACEA A3/B4
  • API SP
  • BMW Longlife-01
  • MB-Approval 229.3/229.5
  • MB 226.5 SFU
  • RN 0700 / RN 0710
  • VW 502 00/505 00
  • Porsche A40
  • Chrysler MS-12991
 
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