Interesting discussion I came across HERE
LQ is a member here too but he offered some good info on this site.
[ August 26, 2006, 01:15 PM: Message edited by: Bio-T ]
LQ is a member here too but he offered some good info on this site.
quote:
Hello all.
I would like to agree that Total Base Number does neutralize acids caused by combustion by-products, but it does not keep contaminants in suspension.
To a large degree, the acidic combustion byproducts are a result of a reaction with sulfur in the fuel. With the introduction of low sulfur gasoline in the US several years ago (sulfur in gasoline cause the rotten egg smell) and the imminent introduction of low sulfur diesel fuel (because sulfur contributes to particulate emissions) the balance of good performance oil formulations has tipped away from high initial TBN. And in practice, the many additive types that provide TBN have different initial values and consequently the better measure is TBN retention.
The additive that keeps contaminants in suspension is a dispersant. High dispersancy prevents sludge "puddles" and oil thickening. As a side note, it may even cause a new oil to turn dark quickly, since it picks up deposit related materials left from the previous oil charge
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We use a blend of PAO and esters. PAO tends to shrink seals, esters to soften them, so a mixture is ideal for elastomeric materials to maintain the original shape. Also, we prefer to formulate with friction modifiers (we use two distinct families of FMs) to provide that activity on the metal surface rather than polar ester base oils.
Our approach is to ensure maximum engine performance and reliability. To that end, there is (to over simplify) a dual system of detergents, dispersants, anti-wear, and friction modifier systems in the formulation. One group covers the performance needs of street performance, gasoline engines, and moderately severe temperatures. The other group performs in the higher temperature arena of diesel engines. In north America, think of turbo-charged tractor trailers that operate at high loads for extended periods, passing significant quantities of soot, blow-by and fuel components into the oil. Those conditions represent racing conditions reasonably well.
Historically, not using detergents was an artifact of some racing engines consuming oil. Organo-metallic additives would cause combustion chamber or piston top deposits, leading to pre-ignition. That's not the case in modern engines. The only technical challenge is balancing the activity on the metal surface between detergents and friction modifiers, which can be done. Motul 300V products do have calcium and magnesium detergents
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We use a diester rather than polyol esters and formulate with the additive(s) to manage the overall formulation characteristics.
The F1 engines run to 19,000+ and use 0W-20.
No, you can't tolerate wear and still expect to have low friction. Low friction is the sum of low fluid friction (oil pump effort, hydrodynamic bearings) and low boundary lubrication (valve train, cylinder walls.) The first is a function of viscosity, the second is a function of additives that are bound to the metals surfaces.
TBN is only a measure of the chemical strength to neutralize acids, and is also only a point of reference for when the oil is new. It helps to control corrosive attack from the exhaust blow by, especially if it chemically reacts with sulfur in the fuel. Initial TBN does not predict TBN retention, or how long this performance lasts. By itself it's not necessarily a good indicator of change interval length.
The focus is on engine performance and reliability; not necessarily fuel economy or extended drain (although those attributes are there.) Low friction, protection in all engines under the broadest performance envelope, and durability of the oil are key. Read more by clicking the "technical" button on the engine oil product page on our site.
I can't say if any other oil companies sell exactly the same formulation. I mean that even if I knew, I could not tell. But read the advertising...
As touched on above, a thinner oil with proper additive treatments, will provide a benefit. The practice depends on somewhat on monitoring oil temperatures, engine components that use the oil as a hydraulic fluid (variable valve timing controls) and oil pump pressure settings.
The oiling system has a certain amount of "spillage and splash" to lubricate valve trains and cylinder walls. This depends on mechanical design such as the diameter of a squirt nozzle. You would want to know if the oil pump has enough volume and pressure to prevent bleeding down too much at the end of a lubrication passageway.
[ August 26, 2006, 01:15 PM: Message edited by: Bio-T ]