Choosing between 0W40 and 5W40

[il_signore97]

Originally Posted By: volodymyr


Thanks for your input. My dilemma is actually very simple. The price difference between A3/B4 and C3 is negligible (1 USD diff per liter) so I want to take the best oil possible.

Overall, I have two hesitations:

1. Since price diff is very small I am choosing between Castrol MAGNATEC 5W-30 C3 and CASTROL
EDGE FST 5W-30. Most of you folks, do tend to suggest me to buy Edge, however I can see that Edge 5W-30 is not Vollsynthetik.

2. I can buy Vollsynthetik Castrol EDGE Titanium FST 0W-30 however this is not 5W-30, but 0W-30. And most of you say that since Nissan recommends 5W-30 I should stick with it.

Which one is better? Following Nissan's recommendation and using 5W-30 or buying Titanium FST Vollsynthetik but 0W-30?



As I stated above, a 0W-xx oil will satisfy all of the requirements of a 5W-xx oil with the exception that you will get better extreme cold weather performance. Although I understand your concern with respect to the recommended grade that Nissan specifies, but considering that your warranty is up and there are no "legal" issues to deal with, a 0W oil will perform just as well as a 5W oil in your engine and application. Not that it is necessary, but you don't need to avoid it just because it is not explicitly stated in the manual.

Also, regarding A3 and C3 oils, there has been some discussion recently that a higher-SAPS oil (such as A3) does indeed offer better protection than lower-SAPS oils (C3) when they are allowed to be used. This is not my information, so don't shoot the messenger. Take it with a grain of salt

So in other words, since your car does not require a C3 oil exclusively, if it were me, I'd be buying only A3/B4 oils for it if I could.

 

[wsar10]

Originally Posted By: il_signore97
Originally Posted By: wsar10
I'm still kind of unclear regarding the answer to the original question, 0w or 5w better for an engine ?

I just went through a similar decision and chose 0w (0-40GC) for the upcoming PA fall and winter, my concern was the same thing...

Is 5w better due to increased PSI at start or worse because its heavier,
on the other hand
Is ow better due to quicker flow rate or worse due to lower ability to maintain coverage ?

Please excuse my improper terminology....... I guess I just need a bit of clarification, please don't give me the automated "what the manual calls for" response, Its my understanding we are all here to dig a bit deeper than OE recommendations to find or verify the best solution.



There is never a simple answer to this question, because the SAE grading system is inherently hard to fully understand. To put it in the most simplistic terms, if your vehicle requires a 30 grade oil, then a 0W30, 5W30, 10W30, etc will satisfy the requirements of your engine at operating temperature equally (notwithstanding the differences in quality of oil and different brands / types available).

The biggest difference between 10W, 5W, and 0W oils are their extreme cold temperature performance. The SAE found it necessary to set MRV (low temp pumpability) and CCS (low temp cranking performance) limits on oils to prevent cars from not being able to start, or starting but not having a steady flow of oil being pumped up everywhere.

For a 5W, these limits are set at -30C for the CCS test, and -35C for the MRV test. The 0W has to pass the same tests but at -35 and -40C respectively.

What does this mean to the average person? Choose the appropriate grade of oil that will encompass the entire temperature range that you will be expecting between now and your next oil change. Also, since the advent of modern day synthetic oil, it is not really necessary to change your oil selection based on cold and hot weather. You can usually find a one-size-fits-all grade that will meet all of your requirements. Back in the day (with respect to conventional oil) people used to use a 5W30 in the winter for cold temperature performance, but switched to a 10W30 in the summer to attain a better shear stability in the heat. Not necessary with synthetic, where a 5W30 or even 0W30 will be suitable all year round, and have all of the shear stability that you will need in most cases for a daily driver.

Now in terms of your question, in normal PA winter temperatures, either a 5W30 or 0W30 synthetic will be fine. Assuming that the 0W30 synthetic is a bit thinner at extreme low temperatures you might end up with a slightly lower oil pressure reading on start-up and warm-up. Remember, you don't need a higher oil pressure for lubrication, you just need a sufficient pressure. At a hot idle, you may only have 10 psi of oil pressure (and that's all that's needed - more is not better or worse, it's just more).

Hopefully this makes a bit more sense.


that makes sense, My concern with oil PSI (for my specific application between 0-5w) was regarding a low oil pressure issue with fords 4.0 and some guys relating that to TC tensioner issues (hydraulic set).

How long does an "oil film" or oil presence hold in the top end of an engine, and is there any notable difference between the 2 weights ?

 

[il_signore97]

Originally Posted By: wsar10


that makes sense, My concern with oil PSI (for my specific application between 0-5w) was regarding a low oil pressure issue with fords 4.0 and some guys relating that to TC tensioner issues (hydraulic set).

How long does an "oil film" or oil presence hold in the top end of an engine, and is there any notable difference between the 2 weights ?


You can look at this a different way... Any oil, regardless of grade (it can be a 0W20 for the purpose of this example) is extremely thick when cold.

So, a 0W20 would be thicker at 30F than a 5W30 would be at operating temperature (180F). Imagine how thick your 5W30 would be at -10, -20, etc... If your Ford does not have any low oil pressure issues at full operating temperature on a 30 grade oil, then it most definitely will not have issues when it is cold started with a 0W oil in it.

However, if it does have oil pressure issues at operating temperatures, a quick band-aid fix would be to increase the operating viscosity (i.e. move up to a 0W40 oil). Then you'd still get the low temperature cranking ability that you desire, but you'd have a thicker film at operating temperature.

All engines will always be coated in oil between uses regardless of grade used, so no worries there.

 

[volodymyr]

Originally Posted By: il_signore97


[...]

Also, regarding A3 and C3 oils, there has been some discussion recently that a higher-SAPS oil (such as A3) does indeed offer better protection than lower-SAPS oils (C3) when they are allowed to be used. This is not my information, so don't shoot the messenger. Take it with a grain of salt

So in other words, since your car does not require a C3 oil exclusively, if it were me, I'd be buying only A3/B4 oils for it if I could.



Well, the problem with this approach is that in the place I shop for oil, they only sell
EDGE Titanium FST 0W-40 A3/B4 which is not 5W-30 or 0W-30 ...

Which brings me back to kinda original topic question ...

Can you please send me the link regarding A3 vs C3 analysis? I will be very happy to read this.

 

[il_signore97]

Originally Posted By: volodymyr


Well, the problem with this approach is that in the place I shop for oil, they only sell
EDGE Titanium FST 0W-40 A3/B4 which is not 5W-30 or 0W-30 ...

Which brings me back to kinda original topic question ...

Can you please send me the link regarding A3 vs C3 analysis? I will be very happy to read this.




There was never anything definitive on this subject other than a discussion, which can be found here:

http://www.bobistheoilguy.com/forums/ubb...ion#Post3351630

I cannot confirm nor deny that anything in that discussion is true or false, but speaking logically, one cannot simply reduce the SAPS levels within an oil without any trade-off. If it wasn't necessary, then it wouldn't be there. Also, Mercedes has been recommending only high-SAPS oils for their gasoline engines, and mid to low-SAPS oils for their diesels exclusively - no substitutions. There also must be a reason for this. I am lead to believe that it is about TBN retention over long drain intervals, but could also be about absolute wear limits. In any case, I will stick to my assertation that if a C3 oil is not exclusively required, then I won't be using it (except in DI engines where they might benefit from the lower SAPS levels in other ways).

Back to your viscosity question... Seriously, I think you're over-thinking this!!! Put it this way... Your dealer has been using 5W40 in your Nissan for quite sometime now, and nothing bad has come of it, nor would I have expected anything bad to occur. Also, I'm certain if you refer to that temperature chart in your manual, you will see that 40 grade oils should also be allowed despite the 30 grade recommendation.

In that case, and given your local supply issue, I would choose the 0W40 A3/B4 Castrol oil without hesitation. I have used 0W40 in place of 5W30 in many cars/trucks without issue, and vice-versa. Under the right conditions, you simply won't have any issues if the viscosity choice is reasonable for the given conditions.

I actually have 2 jugs of the Castrol 0W40 A3/B4 oil waiting to be installed in my C300 -- first time trying Castrol in it!!!

 

[Shannow]

Backing il_signore97 since I've done some more looking.

Same engine with a Renault badge calls for 5W40.

 

[wsar10]

The 4.0 sohc ?

 

[il_signore97]

Originally Posted By: wsar10
The 4.0 sohc ?



No, Shannow was referring to the OP's Nissan Qashqai engine (Nissan and Renault have been partnered for quite some time now).

Just a bit of O/T... The Qashqai is quite a nice SUV. My wife and I had one the last time we were in Italy - we drove almost 3/4 of the country with that SUV. Very comfortable and efficient (mind you, ours had the 1.5 L diesel, 6-speed manual). End O/T!

 

[volodymyr]

il_signore97,

Originally Posted By: il_signore97


I actually have 2 jugs of the Castrol 0W40 A3/B4 oil waiting to be installed in my C300 -- first time trying Castrol in it!!!



Thanks for your comments il_signore97, this is very useful! Last question, if I really want to go for 5W-30, will Valvoline SynPower 5W–30 by any better than Castrol Edge 0W40 A3/B4?

Specs are Vollsynthetik and ACEA A3/B4-10 http://www.autoteile-meile.ch/%C3%96le/Valvoline/SynPower-5W%E2%80%9330/p-OIL-447

 

[il_signore97]

Originally Posted By: volodymyr


Thanks for your comments il_signore97, this is very useful! Last question, if I really want to go for 5W-30, will Valvoline SynPower 5W–30 by any better than Castrol Edge 0W40 A3/B4?

Specs are Vollsynthetik and ACEA A3/B4-10 http://www.autoteile-meile.ch/%C3%96le/Valvoline/SynPower-5W%E2%80%9330/p-OIL-447



No problem. You can absolutely use the Valvoline 5W30 A3/B4 oil in place of the Castrol 0W40 A3/B4. Both oils meet many of the same specs and manufacturer approvals. But for all practical purposes, I doubt that you would notice any difference between the two in terms of protection or operational characteristics.

Even though one oil is a 30 grade and the other is a 40 grade, both oils are in the ACEA A3 category, which means that they both have HTHS (high temperature / high shear) viscosities that are >3.5 cP (both are likely within 0.1 - 0.2 cP of each other). This means that at operating temperature, the apparent viscosity will be very similar, even though the kinematic viscosities are different. You can choose either oil interchangeably based on cost and/or availability.

The only reason that I might recommend the 0W-xx oil over the 5W-xx oil is if you ever encounter extremely cold conditions in which your car will be expected to start unaided (for example, at -35C without an engine heater). For most people though, this is not an issue.

 

[wsar10]

The end reason for going 0-40 was availability of any other weight in GC. The GC seemed to provide very good UOAs with the 4.0 without the iron levels of M1.

 

[volodymyr]

Hello wsar10,

Originally Posted By: wsar10
The end reason for going 0-40 was availability of any other weight in GC. The GC seemed to provide very good UOAs with the 4.0 without the iron levels of M1.


I am trying to understand the meaning of this. Are you implying that Castrol's best UOA are coming from 0W-40 oils?

 

[volodymyr]

Small updated on the topic.

Just before shopping for 0W-40 (or 5W-30) I went to biggest local stores around me to see which oils are usually sold in Switzerland and the viscosity they have.

Overall, there are two main brands standing out: Castrol and Valvoline with viscosity of 5W-40. There are also a lot of 10W-40 and 15W-40.

Since Switzerland does not have the same law like Germany, most of the 5W-40 I assume are HC synthese oils.

I will most likely go for a Castrol Edge FST Titanium 0W-40 since I see a lot of 40s around.

Thanks for your input and comments!

 

[il_signore97]

Originally Posted By: volodymyr
Hello wsar10,

Originally Posted By: wsar10
The end reason for going 0-40 was availability of any other weight in GC. The GC seemed to provide very good UOAs with the 4.0 without the iron levels of M1.


I am trying to understand the meaning of this. Are you implying that Castrol's best UOA are coming from 0W-40 oils?

I think wsar10 was referring to his own situation as to why he chose to run 0W40 in his Ford 4.0L. I don't think it was in regards to your original question.

 

[il_signore97]

Originally Posted By: volodymyr

I will most likely go for a Castrol Edge FST Titanium 0W-40 since I see a lot of 40s around.

Thanks for your input and comments!



Sounds like a good choice to me! Now you can sit back and enjoy your vehicle

 

[Quattro Pete]

Originally Posted By: il_signore97
Now you can sit back and enjoy your vehicle

Agreed. Many of us here on BITOG are guilty of spending too much time worrying and splitting hair. As much as this is the nature of BITOG, we really need to move on and enjoy life.

 

[volodymyr]

Originally Posted By: Quattro Pete
Originally Posted By: il_signore97
Now you can sit back and enjoy your vehicle

Agreed. Many of us here on BITOG are guilty of spending too much time worrying and splitting hair. As much as this is the nature of BITOG, we really need to move on and enjoy life.

))) that is true

 

[wsar10]

Originally Posted By: volodymyr
Hello wsar10,

Originally Posted By: wsar10
The end reason for going 0-40 was availability of any other weight in GC. The GC seemed to provide very good UOAs with the 4.0 without the iron levels of M1.


I am trying to understand the meaning of this. Are you implying that Castrol's best UOA are coming from 0W-40 oils?

My apologies, BITOG REALLY NEEDS an android app. I was typing this while in the DR. waiting room (for an hour)....

No, I'm implying that some of the best 4.0 Ford V6 UOA's are from GC.
I'm speaking to my own application.
I searched high and low for solid UOA's for the FORD 4.0 before and after I bought one, and the GC seemed to ALWAYS provide stellar results IN THIS ENGINE.

My main purpose for going with 0-40; You cannot find GC in any other weight other than 0-40 in my area, plus I wanted a 40wt to improve oil PSI in the 4.0 which is said to have lower oil pressures.

 

[volodymyr]

Hey folks,

(don't worry, I really decided to go with edge 0w-40 and I am not going to change)

A little bit of offtopic. When doing research regarding castrol, I saw that in some forums people say that usually when you use GC especially, it is consumed quite a lot and you have to buy some extra oil so that you can add it. Some people say per 10k km you need 1 liter of oil.

None of my vehicles consume oil, and I wonder if castrol is prone for burning. If all seals are fine, it should not be consumed, right?

 

[glxpassat]

My engine uses less Castrol than it does M1, but my engine has consumed a little oil since new. If your motor doesn't do it now, it probably will not using Castrol.