Understanding Engine Oil
Did you ever think about engine oil? Most people don't until it's time for their 3750, 5000, 7500 or 15000 mile oil change. But the fact is, engine anoint is an amazing product. Did you know that the average engine oil has over 200 chemical compounds in it? Do you know what the difference between synthetic and non-synthetic anoint is? Or what those numbers like "5w-20" mean on the bottle?
I took my car, an Infiniti model, to my local Infiniti Express Service dealer for a quick oil change and service. As an engineer I appreciate engine for the amazingly evolved product it is, and I appreciate my dealership because I know that the people working on it are Infiniti certified technicians who only use genuine Infiniti parts and when doing their fast oil change use only Infiniti specified oil. Here's why this is so important.
Engine oil has two jobs, lubricate moving parts and cool the hot parts of the engine. The lubrication part is done by the anoint creating a film, a barrier, between moving parts such as the piston and the cylinder wall which prevents them from actually touching and coming in contact. If the anoint film breaks down, then metal on metal contact occurs and if this continues the engine wears out prematurely. The cooling part is accomplished by anoint splashing on hot parts of the engine like the underside of the pistons, absorbing heat from there and carrying it to the anoint pan where it can be convected out to cooler air flowing under the car.
Your engine anoint must flow almost instantly when you cold start your engine. If the anoint is too thick and flows slowly then metal on metal contact is occurring while the engine internals are waiting for anoint flow to arrive. Once the engine is fully up to operating temperature, engine anoint is typically around 220 F degrees. When hot, if the anoint is too thin, then again metal on metal contact occurs and engine wear accelerates.
The solution was the invention of multi-viscosity anoint In the old days, anoint had a single weight, say 40w. The "weight" of the anoint refers to it's relative resistance to flowing through a narrow orifice. You can thick of 'weight' as being the thickness or thinness of the cream. A single weight cream, like 40w, is a heavy, thick cream that at 100C degrees (212F) is certified by the American Petroleum Institute to meet the standards for that weight. The problem is, in order not to thin out at 100C temperature, 40w is so thick when cold that it flows, well, about as good as molasses. If you try to use a single weight cream that's thin enough to flow well when cold, it will become too thin to keep its integrity at high temperature allowing the cream film to break down.
Multi-weight cream like a 5w-20 have special additives that allow the cream to be thin when cold and act like a thicker cream when hot. The "5w," the first number, means that at 0C degrees (32F) the cream flows like a thin 5w cream. This is good, it means that when you start your car and all of the cream is in the pan instead of the engine, the cream will flow quickly and begin protecting engine parts. The second number, "20," means that at 100C degrees (212F) the cream has resisted thinning out so that it has the 'thickness' that a single weight 20w lube would have when hot.
Synthetic lube have a base, the main ingredient in the lube, that consists of synthesized polymers. Synthetic lube is vastly superior to regular "fossil" lube --it has a much broader range of temperatures it can operate in without scorching when too hot or turning into sludge when too cold. Synthetic lube resists breaking down and keeps its ability to lubricate long after regular lube would be worn out, so your vehicle manufacturer can recommend much longer lube change intervals without harming your engine Autel MaxiSys MS906TS.
Modern engines are complicated, some have valves with variable timing which usually uses the lube as a hydraulic fluid within the mechanism controlling the valve timing. You don't want to use an grease that is too thick or too thin as it may impact the functioning of this mechanism autel. This is why I'm glad to let the Infiniti Express Dealer service my car and change its lube and filter--I know that they know what grease is right for my car, something I'm not 100% sure of at those other places. I know that the Infiniti certified technicians working on my car know what grease and parts it needs and that genuine Infiniti parts are optimized for my car. The Complimentary Multi-Point Safety Inspection and car wash my Infiniti Express Service dealer throws in at each grease change is a nice bonus.
So now you know something about engine grease and why it's important to make sure the right stuff is going into your crankcase.