Why isn't High Mileage oil the "standard" oil?

[rondhol]

I have not found the exact document. I only observed it in the market with big brand names. So far in Amazon.co.uk or Amazon.de, the only fully synthetic oil labels are found in older Aral, Shell Helix Ultra GTL, and some Ravenol (VSE, FSE, RNF) for the 0w-20. Newer Aral is no longer has fully synthetic label. For instance, Ravenol has VSE (PAO) and VSH (group III) for approved 508/509 oil. The VSH only labeled as synthetic, not fully synthetic like VSE.

I just want to point out that in Europe we accept GTL as fully synthetic, but not regular HC synthetic. Although API categorize both as group III.

 

[Bill_W]

If it has no ill effect, then why not?

IMO high mileage oils are used when you have leaky seals. If you use it before that it will cause leaky seals if you return to another oil. When Mobil 1 first came out it caused leaky seals, the other side of the coin.

 

[kschachn]

IMO high mileage oils are used when you have leaky seals. If you use it before that it will cause leaky seals if you return to another oil. When Mobil 1 first came out it caused leaky seals, the other side of the coin.

Really? The stuff you learn. I wish the blenders would tell you this, I wonder how they get around the API seal swell limits?

 

[rondhol]

Mobil 1 initial PAO oil was using group 1 to increase solubility with the polar additives. PAO itself shrink rubber and older cars have less durable rubber and gasket too.
Now most PAO blend also contains Ester and Polyalkile Naptha that increase solubility, more stable than group 1 oil. Most Ester have swelling property and counter the shrinking effect of PAO.

 

[ltslimjim]

IMO high mileage oils are used when you have leaky seals. If you use it before that it will cause leaky seals if you return to another oil. When Mobil 1 first came out it caused leaky seals, the other side of the coin.

I think this is fear based on the old truth over-swelling did occur. Is there proof it still occurs today? Some use HM oils early on and maybe swap back later, but even if leaks occur afterward, is that alone proof that oil is the cause? Inconclusive at best most of the time I’d say.

 

[rondhol]

These days, we use mostly fluroelastomer rubber for seals and silicone sealants. A very stable elastomer that won't shrink or swell from chemical or heat exposure. The high mileage oil probably affects mainly some rubber parts like valve cover gaskets. So, the effect is minimal, in modern engines.

 

[OilUzer]

I asked one oil if it was on crack and didn't get a good response due to language barrier. Oil no understand English today. We speak no Oil.

Then I looked on the back of the jug and the approvals were in English and much easier to understand. Still a bit confusing VW this, MB that, BMW xyz, Porsche, etc. but it will do.

 

[rondhol]

Generally, European brands have their own certificatio, but overall can be classify using ACEA standard Oil, they are suitable for gasoline and light duty diesel. Meanwhile, API SN, SP, etc. is the standard for most Asian and American gasoline cars.
For instance, ACEA C6 is like the generic for BMW LL17 FE++, VW 508/509, Porsche C20, Dexos D, MB..., etc. They are all within the margin.