“5W-50 too much VII” but 0W-40 “Great oil” why?

[ammolab]

I often see that 5W-50 synthetics are disliked by some as they may be loaded with VII, but most (maybe the same guys) love 0W-40 oils as “great”, “universal“, “good base stock”.

The viscosity spread in these two oils are almost the same. Can’t 5W-50 have as good a base stock or better as the much loved 0W-40 oils? I have used the 0W-40 M1 FS for 22 years with no complaints and have the 5W-50 in my BMW R1200R with no worries.

 

[BMWTurboDzl]

I often see that 5W-50 synthetics are disliked by some as they may be loaded with VII, but most (maybe the same guys) love 0W-40 oils as “great”, “universal“, “good base stock”.

The viscosity spread in these two oils are almost the same. Can’t 5W-50 have as good a base stock or better as the much loved 0W-40 oils? I have used the 0W-40 M1 FS for 22 years with no complaints and have the 5W-50 in my BMW R1200R with no worries.

Perhaps as a whole 5w50 shears more than 0w40's? 5w50 is essentially only used in racing applications anyways.

 

[CR94]

... 5w50 is essentially only used in racing applications anyways.

Therefore ammolab's question would seem more relevant to 10W-40.

 

[ammolab]

Perhaps as a whole 5w50 shears more than 0w40's? 5w50 is essentially only used in racing applications anyways.

Do we KNOW that 5W-50 shears more? Or is that an assumption? Both Castrol and Mobile make 5W-50 street oils.

 

[kschachn]

Also, shear of the VII (if it even is occurring) is highly dependent on the engine design as well as the quality of the VII. So it’s not a universal. Base oil molecules do not shear so everything is dependent on the specific oil and specific engine.

 

[Accent Abuser]

I have some 5w-50 Mobil and have used it a few times, it has all of the Euro certs and Porsche a40 whereas 15w-50 is only ACEA A3/B3. If someone wants a 50 weight I see no reason to use 5w-50 over 15w-50 unless you have cold winters.

 

[robertcope]

I have some 5w-50 Mobil and have used it a few times, it has all of the Euro certs and Porsche a40 whereas 15w-50 is only ACEA A3/B3. If someone wants a 50 weight I see no reason to use 5w-50 over 15w-50 unless you have cold winters.

To your point, M1 5W-50 has a lot of good certs. Why wouldn't I use it instead of 15W-50? (In fact, I do have it in my Ferrari 308 right now!)

 

[Astro14]

I often see that 5W-50 synthetics are disliked by some as they may be loaded with VII, but most (maybe the same guys) love 0W-40 oils as “great”, “universal“, “good base stock”.

The viscosity spread in these two oils are almost the same. Can’t 5W-50 have as good a base stock or better as the much loved 0W-40 oils? I have used the 0W-40 M1 FS for 22 years with no complaints and have the 5W-50 in my BMW R1200R with no worries.

Are they the same, though?

Do they both take the same amount of VII?

The basic point is that the VII shears, and the viscosity suffers. So, if the 5w50 requires more VII to meet the “50” part than the 0W40 requires to meet the “40” then that 5W50 is more susceptible to that shear and viscosity loss.

 

[ammolab]

Are they the same, though?

Do they both take the same amount of VII?

The basic point is that the VII shears, and the viscosity suffers. So, if the 5w50 requires more VII to meet the “50” part than the 0W40 requires to meet the “40” then that 5W50 is more susceptible to that shear and viscosity loss.

They are not the same. But The viscosity spread is almost the same and nobody knows the amount of VII in each, OR the quality of base stock in each. Somehow 5W-50 is feared by some and 0W-40 gets raves by most. That’s my question. Why rag on 5W-50 because of “so much VII…So much shear“ when they both seem to have the same risk.

 

[tnt_motorsports]

Perhaps as a whole 5w50 shears more than 0w40's? 5w50 is essentially only used in racing applications anyways.

And in Tuff Torq lawn mower transmissions

Just my $0.02

 

[kschachn]

They are not the same. But The viscosity spread is almost the same and nobody knows the amount of VII in each, OR the quality of base stock in each. Somehow 5W-50 is feared by some and 0W-40 gets raves by most. That’s my question. Why rag on 5W-50 because of “so much VII…So much shear“ when they both seem to have the same risk.

The quality of the base talk is pretty much irrelevant for shear, it would be the quality of the VII that’s important. The quality of the base stock will determine how much VII is required, but no matter what the base stock is it’s not going to shear.

 

[Kalle.J]

In Europe 5W50 is priced the same as any other Valvoline, Elf, L-Moly a3/b4 run of the mill oils. Often time cheaper then M1 0W40
Ran 5W-50 (the one below) in the CRX one summer, maybe placebo but it felt like it lost a couple HP , slightly less response etc.

This one is equivalent to 6usd a quart. Cheap autopart store brand (similar to supertech I guess)

https://docs.biltema.com/v2/documents/file/sv/4d76a986-2a3a-4f2d-b911-3ef81e8d8a55

Edit: Relevant?
Due to the USVO® technology we achieve an extremely high viscositystability. We avoid the disadvantages of polymeric viscosity improvers whiletaking advantage of them. This improves engine protection, performance,engine cleanliness and oil drain intervals. The USVO® technology makes itpossible that the product has no shear losses during the entire changeinterval and is extremely stable to oxidation

https://www.ravenol.de/storage/app/media/product-pdf/Tds_1142100_en.pdf

 

[ammolab]

The quality of the base talk is pretty much irrelevant for shear, it would be the quality of the VII that’s important. The quality of the base stock will determine how much VII is required, but no matter what the base stock is it’s not going to shear.

Exactly…so the 5W-50 could have a higher quality base stock and less VII and thus be LESS likely to have as much shear risk as 0W-40. Now this is unknown, but many still mention ”that’s gonna shear”. It is all an assumption.

 

[Astro_Guy]

It's an interesting question, but one can only wonder of the relevance in a world dominated by 0W-20 requirements. All four vehicles in my driveway dating from 2010 to 2017 call for 0W-20. I will admit to being off the reservation with one running 5W-30. I will also freely admit that it gets a lot warmer in Arizonza, but why would you need an XW-50?

 

[Kalle.J]

Without knowing your exact engine codes. I can still fairly confidently tell only your Ford "require" 0W-20 ROW. (Rest of world)

 

[Revving2Redline]

I'd run a Amsoil,Redline or Highperformancelubricants 5w50 but I usually saw that wide range of oil as shearing rather quickly especially from commodity oils as people are usually fixated on price point over anything else.

 

[350Rocket]

And in Tuff Torq lawn mower transmissions

Just my $0.02

And hydro gear (my cub cadet takes 20w50 and I noticed the local ope shop stocks m1 5w50 only).

 

[Titan]

Instead of all the spread being due to VII's, how about the possibility of using PPD's (pour point depressants)?

 

[wpod]

Do we KNOW that 5W-50 shears more? Or is that an assumption? Both Castrol and Mobile make 5W-50 street oils.

I would guess a UOA would be a decent method of proff.

 

[kschachn]

I would guess a UOA would be a decent method of proff.

Only if the UOA can properly distinguish between fuel dilution and actual mechanical shear of the VII. And if it can properly measure viscosity. And if you have a VOA to make a proper comparison since the viscosity values in a PDS are not specific to the lot or batch. At least one blender doesn't even give typical values on their PDS but merely grade requirements.

A proper and dedicated test such as ASTM D6278 is the correct method to determine shear stability in oils.