What do dispersant oil additives do?

[@LubricationExplained]

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[@1wisestein]

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[@LubricationExplained]

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[@ThisisMeLouana]

This is a very good information video.

[@LubricationExplained]

Glad it was helpful!

[@JeevanPradhanG1]

Very nicely explained sir

[@luizfernandopaquieli3709]

Such a great class! Thanks for sharing!

[@LubricationExplained]

Glad it was helpful!

[@PedroGoncalves-cp9ql]

Dear Sir, do know any good dispersing of PTFE nano particles in mineral oil? Where i could found it comercial?

[@watercooled8105]

Is there an acknowledged ratio of detergents vs dispersants in automotive motor oils? Or would both be over-based equally? Also, when motor oils fail to suspend contaminates, is this generally an exhaustion of the dispersants or a breakdown of the dispersant molecules?

[@MrSensible2]

Typically your car's oil will contain 2 - 3% of over-based detergent & 4 - 6% of ashless dispersant (ashless is never 'over-based'). There's no hard & fast ratio. At a rough guess, 99.9999% of the world's engine oil is tossed long before it gets anywhere close to its true exhaustion point. All oils are massively over specced for their intended duty so I personally wouldn't worry about it.

[@watercooled8105]

With the (quantity) percentage set in a certain range, if I were to look at a data sheet for an automotive motor oil listing dispersants, what would indicate high quality dispersants are being used?

[@MrSensible2]

@@watercooled8105 Short answer?Absolutely nothing! The amount of Nitrogen in dispersant is piddling & the actual physical measurement of Nitrogen in engine oil is always problematic. You might be able to infer it from the amount of Boron in the oil (Boric acid is a common dispersant capping agent) but this is very hit and miss as some ashless dispersants either aren't capped or use a capping agent (like Glycolic acid) which doesn't contain Boron. Basically, as a consumer, you're stuffed!

[@sunrevolver]

In an engine oil, there are mixed of low over base detergent, high over base detergent and ashless dispersant. Detergent has limited dispersant activity and dispersant has limited detergent activity. Depending on the exact type used, the ratio and combination will differ.

[@sunrevolver]

​@@watercooled8105you can't really determine whether the dispersant used is of high quality or not. There are many combinations to get an oil passed all the required testings. It's like saying how can we know the quality of a sugar in a cake.

[@MrSensible2]

To me, ashless dispersants are primarily a 'diesel thing'. Everything you said about soot dispersancy & piston cleaning I'd 100% agree with. However, when you really dig into it, ashless dispersants don't make a great deal of sense for gasoline engines. They don't actually prevent sludge formation or deposition. If you want to attack a sludge issue, you're far better off on focusing on the oxidation resistance of your oil. Also, in many respects, ashless dispersants make gasoline focussed oil worse. They push up Noack volatility & can worsen seal compatibility. Here in Europe, you generally get lots of ashless dispersant in PCMO because it's always specced for BOTH gasoline & diesel. However, to me, the, Yanks have been getting this fundamentally wrong for decades.

[@LubricationExplained]

Yeah absolutely. Must be hard for formulators trying to satisfy the requirements of completely different applications.