Understanding my oil...

[D4N]

Hi All,

I am undertaking an oil change and wanted to know what the best oil is for my car (within reason, I.e. available at Repco and the like). After reading the service guide and a bit research I thought I would share my findings (I am not saying it is right, just what I found). I thought this might be helpful for someone like me that has less experience/knowledge than most of you on this forum.

This is the for the FG Mk2.

The service manual states the following (p.27) ‘The Ford Motor Company recommends the use of SAE 15W40 API SJ/CF meeting the requirements of…’.

I already had used the Penrite app and website to purchase the HPR 10 10W-50 (Full Synthetic) but thought I should check before I started the service.

I was interested in ‘SAE 15W40 API SJ/CF’, so I thought I would break this down.

1.       SAE stands for Society of Automotive Engineers. The SAE developed a classification system to define the viscosity or thickness of oil. This acronym at the start just puts the classification system into context.

2.       The first number in signifies the viscosity of the oil at cold/start up temperature (tested at -10 to -35°C depending on the grade). The “W” stands for winter. The lower the first number, the faster the oil flows (pumpability) when the engine is cold. This translates to better protection at start. Higher numbered oils mean that the oil is thicker at start and can’t be as easily ‘pumped’ into the engine.

3.       The second number represents the oil’s thickness at operating temperature (100°C). All oils thin out as they get hotter. So, the higher the second number, the less the oil will thin out as it heats up (or breakdown in extreme cases), compared to an oil with a lower second number.

Apparently, you don’t want the oil to be too thick at start up and don’t want it too thin at operating temperature. That is, it seems preferred for the viscosity to remain more constant over all operating temperatures. Of course, this is all in relation to the manufacture's recommendations.

The API SJ/CF part…API stands for the American Petroleum Institute. The API have established technical standards and testing procedures. The first letter in each block represents the type of oil. ‘S’ stands for spark ignition and ‘C’ stands for compression ignition. Different websites have slight variations (such as ‘C’ stands for commercial) but the ones above seem most plausible.

For interest there is also a Diesel F category.

Focusing on the SJ, the ‘J’ is the API Service category. This is alphabetical, so L is a higher category than J. The later or higher API Service Categories includes the performance properties of each earlier category and can be used to service older engines where earlier category oils were recommended.

Ford recommends a SJ service category, the Penrite oil is SN which is a later and higher service category. So the Penrite covers the SJ service category and is OK to use.

Synthetic Oil – some points I found and thought were interesting

1. At start-up, mineral oils take longer to circulate in an engine meaning more friction.
2. Synthetic motor oils are not ‘artificial’ or 'fake'. They are derived from crude oil, natural gas, or other chemical feed materials; however, as a general rule they use more extensively processed, higher quality base oils than conventional motor oils.

3. Synthetic oil is engine oil that’s been further refined, distilled, purified and broken down through a process of chemical engineering.

4. Synthetics offer protection across a broader operating temperature range. They are more robust, have low-temperature pump-ability and improved stability at high temperatures.

5. It is a myth that you can’t/shouldn’t use synthetic oil early in the vehicle’s life.

For interest, this is were I got most of the information

www.mobil1.com.au/academy/myth.aspx

penriteoil.com.au/knowledge-centre/what-is-an-sae-viscosity/180

www.royalpurpleconsumer.com/synthetic-oil-myths/

www.valvoline.com/about-us/faq/synthetic-oil-myths

www.api.org/products-and-services/engine-oil/eolcs-categories-and-classifications/oil-categories

www.sae.org/standards/

en.wikipedia.org/wiki/SAE_International

[adams355]

Don't use HPR10 as recommended by penrite. I f you want to use penrite use HPR5. 

 

5W-40 full syn from any of the major players is the best, Castrol, Valvoline, Shell, Mobil One. If we were in the US we would run 5W-30 on the newer cars but that's another story.

 

Look into viscosity index and TBN 

[D4N]

Thanks for the reply - why not use the HPR10? 

 

That is the one Penrite recommends. 

Edited 10/10/18 12:51 PM by D4N

[adams355]

Penrite has this 'extra ten' approach no one really knows why its pretty old advice considering they are using synthetic oil now. The most important number is 40 that's what ford recommends.

[D4N]

Thanks Adams355, off to get some Castrol magnatec 5W - 40 first thing in the morning (after a quick search, I see a lot of people on here use). 

 

Your advice has been a great help once again! 

[adams355]

ok sorry I meant edge synthetic when I mentioned Castrol, the magnetec would work but you said best sorry

[D4N]

Thanks Adams355, off to get some Castrol edge 5W - 40 first thing in the morning (after a quick search, I see a lot of people on here use). 

 

Your advice has been a great help once again! 

 

Ha ha - thanks mate 

 

I knew what you meant - I had a early morning typo  

[adams355]

Thought I put this here my experience

 

Nulon 10w-40 Full syn and K&N oil filter. Car was daily driven with a few long trips it used at least 500ml, had noticeable blow by.  Oil felt tacky and had red tinge at 6500km oil change. 

 

Vavoline Synpower 5w-40 and Aeroflow oil filter. Car was daily driven, a few long trips, 2 dyno tunes. Oil was still 'oily' used zero oil, no blow by, dyno tuner even commented it didnt blow any smoke at all. Had minor red tinge to oil after 7000km change.

 

Valvoline Synpower 5w-40 with Motorcraft FL-280S should be good, give me 6 months.

 

2c

Edited 07/01/19 07:33 AM by adams355