Help with argument

[caveanimal]

I am having a discussion about SAE 5W-20 API SM and SAE 5W-20 API SN the person I was talking to said that the API SN wasn't any better than the API SM and I shouldn't use the API SN I said there was a difference, that the API SN is just newer than the API SM..

Am I wrong or is he the one that is mistaken.

Thanks

 

[V8man]

You are right, he is the one that is mistaken.

 

[Tomek]

Originally Posted By: V8man
You are right, he is the one that is mistaken.


True story.

 

[Gabe]

An oil related question! I have not seen one of those in a while...

SN is more stringent on piston deposits than SM.

 

[Rolla07]

I dont think difference is that significant. All else being equal why not use SN? Unless
SM is half off LOL...whats his argument for not using SN?

 

[Hyde244]

This is a great go to link that gives an overview of API certification classes.

http://www.pqiamerica.com/apiserviceclass.htm

While SN and SM are very similar oils, SN provides better piston and sludge protection. It is also designed to better compensate for ethanol, which for the most part is blended into all gasolines nationwide.

Here is a graphic charting the advantages of SN vs. SM.

Again, a big advantage to SN oil is its compatibility with ethanol. Whether you like it or not, most regular gasoline is now E10, and will most likely increase in ethanol content in the years to come. (such as current EPA proposals to increase to E15 in 2017) Stick with the SN/GF-5 oil until 2015, when the new GF-6 oils are due.

 

[spk2000]

Based on the above chart there would be no advantage of the SM over the SN. Any idea how this chart was made? I could put together a chart like this but have no data to support it.

 

[Hyde244]

Here is the website from which the graphic was pulled, which explains the metrics behind each category.

http://www.oilspecifications.org/articles/api-sn.php

You can also explain to your friend that SM oil is GF-4 specification, and SN is GF-5 specification. Again, here is a graphic depicting the difference between GF-4 and GF-5, which shows advantages in piston cleanliness and fuel economy.

Here is the "main" GF-5 website, which goes in depth on the advantages of GF-5 (which is SN) oil.

http://www.gf-5.com/the_story/performance/

... And as a preview of coming attractions, here is how the new GF-6 will compare to current GF-5. GF-6 is set to be introduced in 2015, and be readily available by 2016. Again, there will have gains in fuel economy and piston cleanliness, as well as the creation of a non-legacy oil that will only be usable in new cars for 2015 and 2016.

 

[caveanimal]

Hey thanks for all the replies. I will have to give my friend a ring and let him know,
Better yet I should show him the replies he might believe me than.


Thanks again all

 

[Shannow]

Originally Posted By: Hyde244
This is a great go to link that gives an overview of API certification classes.

http://www.pqiamerica.com/apiserviceclass.htm

While SN and SM are very similar oils, SN provides better piston and sludge protection. It is also designed to better compensate for ethanol, which for the most part is blended into all gasolines nationwide.

Here is a graphic charting the advantages of SN vs. SM.

Again, a big advantage to SN oil is its compatibility with ethanol. Whether you like it or not, most regular gasoline is now E10, and will most likely increase in ethanol content in the years to come. (such as current EPA proposals to increase to E15 in 2017) Stick with the SN/GF-5 oil until 2015, when the new GF-6 oils are due.


Try this site
http://origin-qps.onstreammedia.com/orig...p/pc/index.html

put in SM and SN, and see how comprehensively they cover the bases.

Then throw in n ACEA C3 spec just for giggles

 

[HyundaiGuy]

Here is something I don't get. I see from the graphic above that SN is clearly superior to SM.

So, why is it that it when it comes to PU, some are saying that SM is better than SN? I can still get PU for now- my local store is still selling SM and that is what I have been using. I am hoping that if I keep buying it, they will restock.

 

[Coprolite]

The PU SM is still good, but the SN is phenomenal*.













*Slight hyperbole, but it is great.

 

[KHP]

Originally Posted By: HyundaiGuy
Here is something I don't get. I see from the graphic above that SN is clearly superior to SM.

So, why is it that it when it comes to PU, some are saying that SM is better than SN? I can still get PU for now- my local store is still selling SM and that is what I have been using. I am hoping that if I keep buying it, they will restock.

Bench racing is quite popular here. The only info we have on oils come from MSDS's, TDS's, VOA's, and UOA's. These tests only show very narrow properties of the oil. So based on the numbers, SM formula may have better additive package than SN formula. The unknown is what other contents of the oil are there that do not show up in the spectral analysis.

So I would go with the SN formula being superior to SM. Us as consumers just don't have enough information to judge these oils properly. Quite a lot of the comments regarding oil formulation being superior than another are a haunch, guess, etc...