Why 5W40 and 0W40 Synthetic ?

[SR5]

Hi All,

With some of the major brands around here you can buy both 5W-40 and 0W-40 full synthetic oil. The 5W-40 oils tends to cost a little less, and probably more significantly (according to my spec sheets) is only MB 229.3 rated, while the 0W-40 is MB 229.3/229.5

So why do they make both? It looks like the 0W-40 is a better oil, so shouldn't they just drop the 5W-40. Or is there an application or manufacturer spec that calls for 5W-40 for a specific reason.

Here are some figures from the PDS

Castrol Edge 5W-40 (Ti)
API SN, ACEA A3/B4, BMW LL-01, MB 229.3, Porsche A40
Vis 40C 84
Vis 100C 14.0
VI 173
PP -42 degC
FP 208 degC
(HTHS 3.8 ??)

Castrol Edge 0W-40 (Ti)
API SN, ACEA A3/B4, BMW LL-01, MB 229.3/229.5, Porsche A40, VW 502/505, Ford WSS-M2C937-A
Vis 40C 79
Vis 100C 13.1
VI 168
PP -60
FP 211
(HTHS 3.6 ??)

Valvoline SynPower 5W-40
API SN, ACEA A3/B4, BMW LL-01, MB 229.3, VW 502/505, RN 700/710, GM-LL-B-025
Vis 40C 81
Vis 100C 13.6
VI 173
PP -42
FP 236

Valvoline SynPower 0W-40
API SN, ACEA A3/B4, BMW LL-01, MB 229.3/229.5, Porsche A40, VW 502/505, RN 0700/0710
Vis 40C 73
Vis 100C 13.3
VI 183
PP -45
FP 242


The HTHS figures weren't from the PDS, I found them in another thread and they look reasonable.

Thanks.

 

[d00df00d]

I bet it's because there are enough people who think 0w-40 is "too thin."

 

[finmile]

And also cheaper oil is better oil.

If someone doesn't need 0W-40 they select 5W-40 as it is cheaper.

 

[Shannow]

It makes an absolute mockery of the BITOGers who have said for years that the only reason Oz owners manuals offered choice was that the bullock carts couldn't bring the oils to the country.

The Japanese companies could bring entire cars to the country, but couldn't bring the "optimum" oil to service them...not even a case oil in the boot.

The fact that we have so many specialty oils available in places like supercheap as opposed to 26 flavours of vanilla in GF-5 dispels the whole wagon train argument.

There's no rational reason for a 0W to be offered in Oz other than it's in the owner's handbook...again dispelling the wagon train strawman.

 

[CourierDriver]

At our Napa store, we are selling a lot of this now....
http://www.eneos.us/products/

 

[rslifkin]

Your specs point out a very clear reason why it's offered: the 5W-40 has higher HTHS and is usually a little thicker when hot. In some cases, a 50 would be thicker than desired (5W-50 is thicker when cold than a 5W-40) but the 0W-40 may not have a high enough HTHS or enough shear stability for the application (or might just be more expensive and not needed).

 

[CT8]

The bigger the visc spread the weaker the film strength of the oil . I would like to see the vii of the base oil rather than the finished product doctored up with viscosity improvers.

 

[Gokhan]

Compare PP Euro 0W-40 and 5W-40. 5W-40 meets a lot more OEM specs than 0W-40, including BMW, Chrysler, Ferrari, and Maserati.

0W-40 is a one-size-fits-all grade that does this at the expensee of a ton of VII, a lot more than any other grade. Most people, except those living in Canada etc., would be equally well off with 5W-40 but only Pennzoil seems to make a good one.

 

[Quattro Pete]

Originally Posted By: Gokhan
Compare PP Euro 0W-40 and 5W-40. 5W-40 meets a lot more OEM specs than 0W-40, including BMW, Chrysler, Ferrari, and Maserati.

There is a suspicion that the reason PP Euro 0w-40 does not carry the BMW spec is because SOPUS has now become an official BMW oil supplier, and they're selling a BMW branded 0w-40 oil, which is of course more expensive than PP Euro 0w-40.

 

[chrisri]

Valvoline Synpower 5w40 meets 229.5 and 229.3.

 

[BMWTurboDzl]

Originally Posted By: Quattro Pete
Originally Posted By: Gokhan
Compare PP Euro 0W-40 and 5W-40. 5W-40 meets a lot more OEM specs than 0W-40, including BMW, Chrysler, Ferrari, and Maserati.

There is a suspicion that the reason PP Euro 0w-40 does not carry the BMW spec is because SOPUS has now become an official BMW oil supplier, and they're selling a BMW branded 0w-40 oil, which is of course more expensive than PP Euro 0w-40.


Fyi...dealer oil is cheaper than retail.

 

[OVERKILL]

Originally Posted By: Gokhan
Compare PP Euro 0W-40 and 5W-40. 5W-40 meets a lot more OEM specs than 0W-40, including BMW, Chrysler, Ferrari, and Maserati.

0W-40 is a one-size-fits-all grade that does this at the expensee of a ton of VII, a lot more than any other grade. Most people, except those living in Canada etc., would be equally well off with 5W-40 but only Pennzoil seems to make a good one.


Which must be why M1 0w-40 is the factory fill and service fill for Mercedes AMG vehicles as well as Porsche

Good Lord man, both M1 0w-40 and Castrol 0w-40 meet all the same approvals/specs as PP Euro 5w-40, your single example of one 5w-40 in the same product line as a 0w-40 from the same manufacturer as proof of 5w-40 meeting "a lot more OEM specs" is ridiculous.

And both 0w-50 and 5w-50 have more VII's than 0w-40 as does 10w-60. Again, another statement tossed out for effect due to the agenda of the poster.

There's no guarantee that a 5w-40 will have less VII's than a 0w-40. A group III 5w-40 may in fact have more VII's than a 0w-40, which are often blended with PAO. PP Euro has, in a myriad of UOA's on this board, shown to shear down significantly, in fact I made a thread about it a while back. This is not something we see with the more recent incarnations of M1 0w-40 and GC 0w-40.

 

[Quattro Pete]

Originally Posted By: BMWTurboDzl
Fyi...dealer oil is cheaper than retail.

How much is it at the dealer's?

 

[Quattro Pete]

Originally Posted By: chrisri
Valvoline Synpower 5w40 meets 229.5 and 229.3.

Not the one we have here available at retail level.

There is Synpower 0w-40 however, that does meet these specs.

 

[Jetronic]

synpower 5w-30 might even meet those specs. 229.5 for sure. I would prefer that over 0w-40 or 5w-40

 

[Gokhan]

Originally Posted By: OVERKILL
Originally Posted By: Gokhan
Compare PP Euro 0W-40 and 5W-40. 5W-40 meets a lot more OEM specs than 0W-40, including BMW, Chrysler, Ferrari, and Maserati.

0W-40 is a one-size-fits-all grade that does this at the expensee of a ton of VII, a lot more than any other grade. Most people, except those living in Canada etc., would be equally well off with 5W-40 but only Pennzoil seems to make a good one.

Which must be why M1 0w-40 is the factory fill and service fill for Mercedes AMG vehicles as well as Porsche

Good Lord man, both M1 0w-40 and Castrol 0w-40 meet all the same approvals/specs as PP Euro 5w-40, your single example of one 5w-40 in the same product line as a 0w-40 from the same manufacturer as proof of 5w-40 meeting "a lot more OEM specs" is ridiculous.

And both 0w-50 and 5w-50 have more VII's than 0w-40 as does 10w-60. Again, another statement tossed out for effect due to the agenda of the poster.

There's no guarantee that a 5w-40 will have less VII's than a 0w-40. A group III 5w-40 may in fact have more VII's than a 0w-40, which are often blended with PAO. PP Euro has, in a myriad of UOA's on this board, shown to shear down significantly, in fact I made a thread about it a while back. This is not something we see with the more recent incarnations of M1 0w-40 and GC 0w-40.

You completely misread my post.

I only gave it as a counterexample because OP made it sound like it's a general rule. Also, if you look at my signature line, I use 0W-40.

0W-40 does use a lot of VII. Yes, 5W-50 and 10W-60 uses even more but hardly anyone uses those grades. A lot of VII is not necessarily bad -- you do get higher VI.

 

[userfriendly]

We have come a complete circle from 10W30 and 5W30 to expensive 0W40 and back again. The 0W40 one size fits all for factory fill global vehicles makes complete sense. It can shear down over the service interval and still perform like a good 10W30. In addition, 0W40 can slip a grade in the winter designation and still provide 5W starting and pumping performance. What is not to like about 0W40? Well I guess the price and maybe the non issue that XW performance is redundant in mild climates. If the HTHS of a 0W40 begins it's life at 3.9 and shears down to 3.6 by drain time, while the 5W30 begins at 3.6 and stays there, the difference becomes mostly initial cost, personal preferance and availability.

 

[Gokhan]

Let's give the facts so that there will be some actual useful information here. Here is the recommended ingredient list for synthetic oil by ExxonMobil. Formulas will vary a little but the following is rather typical:

The difference between 0W-40 and 5W-40 is that 0W-40 starts from a much thinner base oil and uses more VII to increase KV100 to the SAE 40 level. That's the only real difference between the two grades. The end result? 0W-40 benefits from lower CSS/MRV (thanks to thinner base oil) and higher VI (thanks to more VII content). However, 5W-40 benefits from lower NOACK (thanks to thicker base oil) and less oil shear (thanks to less VII content).

Regarding Group III vs. PAO, PCMO Group III has greater or equal VI than PAO these days, thanks to HVI Group III (Group III+) and XHVI Group III (GTL). Therefore, amount of VII content with high-quality Group III can be even less than with PAO. HDEO 5W-40 like Rotella tends to use cheaper Group III with lower VI.

Last but not least, shear-stable VIIs are common these days, resulting in very little degeneration of the overall VII content over time and therefore very little oil shear:

I have been using Mobil 1 0W-40 SN recently and my engine has never run smoother. I thought TGMO 0W-20 SN was great but the Group III+/PAO/ester base oil of Mobil 1 along with a higher-quality additive package seems to have resulted in a truly premium oil.

 

[camrydriver111]

There is no guarantee 5W40 will have less VIs.

I think Castrol 5W40 has more VI than Mobil1 0W40.

 

[Gokhan]

Originally Posted By: camrydriver111
There is no guarantee 5W40 will have less VIs.

I think Castrol 5W40 has more VI than Mobil1 0W40.

How can that be? You would end up with a 5W-50 or 5W-60, or the 0W-40 would end up to be a 0W-30 or 0W-20. It's simple math. Unless the starting VI of the base oils are drastically different, it's mathematically impossible for one of them to be in the intended SAE grade. On top of that, thicker base oils have a higher VI to begin with. So, you are postulating a mathematical near impossibility, unless Castrol 5W-40 PCMO is made from a rather cheap, low-VI Group III.