Robert G. Smits Posted June 26, 2018 Share Posted June 26, 2018 Oil jobber friend just offered me 50 gal of Mobile 1 API rated SM. What is the downside of using it in a 2014 auto that is out if warranty. My research suggests the major difference is mileage additives. Thanks, Bob Smits Link to comment Share on other sites More sharing options...
Spinneyhill Posted June 26, 2018 Share Posted June 26, 2018 (edited) What are "mileage additives"? The first web site I found had this to say. (https://www.oilspecifications.org/articles/api-sn.php "The API SN category is an improvement over the API SM category in the following areas: High temperature deposit protection for pistons Better sludge control Better seal compatibility Aftertreatment compatibility" Edited June 26, 2018 by Spinneyhill (see edit history) Link to comment Share on other sites More sharing options...
Grimy Posted June 26, 2018 Share Posted June 26, 2018 And SM has more zinc and phosphorus than SN. I believe SN replaced SM somewhere around 2014 (check your most modern vehicles' owners manuals for the letter code requirements), so it should be fine for anything pre-2015. Link to comment Share on other sites More sharing options...
Spinneyhill Posted June 26, 2018 Share Posted June 26, 2018 (edited) If you go further down that web site I gave above, there is a general comparison. The SN category was " Introduced in October 2010 for 2011 and older vehicles, designed to provide improved high temperature deposit protection for pistons, more stringent sludge control, and seal compatibility. API SN with Resource Conservingmatches ILSAC GF-5 by combining API SN performance with improved fuel economy, turbocharger protection, emission control systemcompatibility, and protection of engines operating on ethanol-containing fuels up to E85. " This is what it says about SM oils. SM Introduced on 30 November 2004 Category SM oils are designed to provide improved oxidation resistance, improved deposit protection, better wear protection, and better low-temperature performance over the life of the oil. Some SM oils may also meet the latest ILSAC specification and/or qualify as Energy Conserving. They may be used where API Service Category SJ and SL earlier categories are recommended. Based on what it says above, SN is not for your engine and SM is what you should use. As for Mobil 1, there are a lot of them! Which is it? See this table: https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf Also important is the viscosity rating of the oil. What is it? Edited June 26, 2018 by Spinneyhill (see edit history) Link to comment Share on other sites More sharing options...
Grimy Posted June 26, 2018 Share Posted June 26, 2018 Spinneyhill, I did not have time then or now to read the linked article, but am confused by the excerpt you cite. "S" is for "spark ignition" (vs. compression ignition--diesel), and the "N" is even now the latest iteration I've seen. Each successive iteration seems to be geared towards further reducing contamination of catalytic converters. That is, I know of no "SO" or "SP" oil ratings, so 2018 cars in the USA, so far as I know, still call for SN oils. SOME manuals for 2014 vehicles might call for either SM or SN oils. The manufacturers claim backwards compatibility, hence "2011 and older," but each successive iteration has reduced zinc and phosphorus. In sum, I repeat my earlier suggestion to the OP to check his owner's manual to determine whether (1) SN MUST be used, or (2) SM or SN is the spec. Link to comment Share on other sites More sharing options...
Spinneyhill Posted June 27, 2018 Share Posted June 27, 2018 Agreed. Do what the manual says. Link to comment Share on other sites More sharing options...
Robert G. Smits Posted June 27, 2018 Author Share Posted June 27, 2018 Spinneyhill, the graphs you refer to are for current Mobil 1 SN rated oils. The product i was offered is 5-20 Mobil 1 with a SM API rating. My owners manual recommends using SN oil. I will probably go ahead and use the SM rated oil as I think a full synthetic SM probably beats a non synthetic SN. We won't know for another 100K Thanks to all who replied. Bob Smits Link to comment Share on other sites More sharing options...
C Carl Posted June 27, 2018 Share Posted June 27, 2018 Might 5W/20 be a bit light for those hot, IR re-radiating Texas trails ? I assume you are planning to oil some of the rest of the fleet with this big can, not just the 2014 machine ? Please pardon my brash irreverence, but marrying yourself to 50 gallons of an inappropriate oil doesn't exactly seem to me to be a match made in heaven. Why don't you just consult your local Amsoil dealer, and treat your vehicles to the best? Now as always, the disclaimer : I have absolutely no connection whatsoever to Amsoil. I just use it. If anyone can prove a better oil exists, I will switch to it at the next oil change. Amsoil is at the very top of the syntheticity scale, and is touted by Richard Wildman who in turn has no connection to Amsoil. They are very forthcoming with technical data, and you will find that Z-Rod in any combination of the 10W/30 and 20W/50 will be best for most of your cars and trucks. You will find that Z-Rod also currently offers the best corrosion protection for cars which are not daily drivers. For your 2014, Amsoil has a more appropriate oil, even a bit more pricey than Z-Rod. But it is still a great bargain as it is preventative maintenance. How do you doctors put it ? "An ounce of prevention is worth a ton of corrective surgery". Or something like that. From up here in perpetually cool 10W/30land, your forum friend, - Cadillac Carl Link to comment Share on other sites More sharing options...
Spinneyhill Posted June 27, 2018 Share Posted June 27, 2018 (edited) 5-20 or SAE 5W-20? They are different. As Carl says, 5W--20 seems a bit light. If your manual wants 5W-30 (or even 0W-30) don't touch it. As you say, you will know maybe in 100k miles. But if you use the right oil, maybe it will be 300k miles before you know. It would be an expensive bottle of oil if you know too soon. Yes, the table was for SN. SM probably had MORE zinc and phosphor. One of my points was that "MOBIL 1" is not just one oil, it is a family of oils. Which one do you have? Another point was that the "zinc" content varies within that family, as does the purpose of the oil. Use the correct oil. Why do you want to risk a fairly new engine for a bottle of cheap, incorrect oil? The other obvious question is, why doesn't your oil jobber friend use it? What is wrong with it? Edited June 27, 2018 by Spinneyhill (see edit history) Link to comment Share on other sites More sharing options...
Robert G. Smits Posted June 28, 2018 Author Share Posted June 28, 2018 Carl, I appreciate your comments. The oil is SAE 5W-20 along with several gal on SAE 10W-30. Also the oil is FREE as he needs to move it out of inventory. Spinneyhill I didn't realize that Mobil 1 was cheap. The engine in my Ford has been used for years. You are asking me to believe that in 2010 they changed the engineering so SM oil will destroy it. Carl I do use Amsoil in my tow vehicle and tractors. Again thanks to all who have replied. Bob Smits Link to comment Share on other sites More sharing options...
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