Mobil 1 ESP/ X3 vs FS 0w-40

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Mar 10, 2017
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Really?completely? Not even similar?
anyway my comment relates to the needs of my humble car As well as trying out a low sap oil

Totally different specifications.

Also, your car absolutely does not need a low SAPS oil. It won't hurt it. But don't waste your money.
 
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Really?completely? Not even similar?
anyway my comment relates to the needs of my humble car As well as trying out a low sap oil
Yes it is completely. We are not talking the difference between Nestle milk chocolate and dark chocolate.
What YOU want to do is different. You could also try sunflower cooking oil.
 
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My car (2003) recommend API SL for engine oil. I assume the engine is pre GPF.
I have been using Mob 1 0w-40 fully synthetic since new. I have looked at the ESP range because of the slightly different viscocities and availability.

I understand that the API hierarchy means that an SN rated oil meets all it's predecessors specifications like (SJ, SL, SM ...) +additional newer onces.

So I contacted mobil (UK) about suitability of the ESP & EXP X3 for my car compared to FS (full SAP). Theu guy gave me helpful information relating to GPF oil requirement and so on but the outcome was that ESP/ X3, do not meet the SL standard and that I should not use them.

Could it be that full SAP oil is a better lubricant so better for engines without GPF?

So a little confused here. Perhaps our expert members can shine some light on this for my benefit?
Any modern oil with any certification will work in your old car that calls for the long-outdated API SL certification. Use whatever is cheaply available.
 

bonjo

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Aug 26, 2009
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UK
My thinking too.
ESP 0w30 now purchased, similar price to FS 0w40. I was very very lucky to find very good prices at the time.
BTW over the last 6 months prices have gone through the roof and product avalability down the sink.
 
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Not to scare the op or spoil the party but iirc, SonOfJoe said API SL is not as harsh on seals i.e. it's more seal friendly!

I kind of remember that because at the time, I was considering some 0W-30s (Castrol?) but it was API SL (i.e. old classification). He talked about it being Full-SAPS ... and also more seal friendly!
Not sure if I asked or can't remember how API ratings can have an impact on seals ... maybe due to chemical compound amounts, limits, or lack thereof. I assume they all should pass some sort of seal compatibility test(s) but some may do better!
If I can find the discussion, I will attach the link.

Having said that, I read that API ratings are backward compatible and maybe hard(er) to find API SL ... so theoretically, op should not worry! :)
 
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OVERKILL

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Not to scare the op or spoil the party but iirc, SonOfJoe said API SL is not as harsh on seals i.e. it's more seal friendly!

I kind of remember that because at the time, I was considering some 0W-30s (Castrol?) but it was API SL (i.e. old classification). He talked about it being Full-SAPS ... and also more seal friendly!
Not sure if I asked or can't remember how API ratings can have an impact on seals ... maybe due to chemical compound amounts, limits, or lack thereof. I assume they all should pass some sort of seal compatibility test(s) but some may do better!
If I can find the discussion, I will attach the link.

Having said that, I read that API ratings are backward compatible and maybe hard(er) to find API SL ... so theoretically, op should not worry! :)
Elastomer compatibility test I think is what you are referring to.
Screen Shot 2022-02-16 at 7.09.12 PM.png


It looks like the diesel oils are a bit stricter, here's CJ-4 (same test number, but amusingly, they change the name):
Screen Shot 2022-02-23 at 1.49.42 PM.png

And CK-4:
Screen Shot 2022-02-23 at 1.49.21 PM.png
 
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