Above all, engines run smoothly, thanks to sophisticated, Lubricants And Oils.

So, Lubricants can be a fluid, solid, or semi-solid. However, Engine Oil, refers to a liquid lubricant, with an oil base and additives.

During winter, the same engine oil, has to operate over temperatures, ranging from -40 °C to above 250 °C. And, that’s why, Lubricants And Oils, are remarkable fluids.

Above all, Lubricants And Oils, must deal with these conditions, every day for up to two years.

Subsequently, the recommended time between oil changes, according to some vehicle manufacturers. They also, have to deal with, contaminants, including metal particles, sludge and soot.

So, What Are They?

Engine Lubricants And Oils, Play Four Major Roles:

  1. Control friction and wear in the engine
  2. Protect the engine from rusting
  3. Cool the pistons
  4. Protect the engine oil, stored in the sump from combustion gases

Also, There Are Four Distinct Types, Of Lubricants And Oils:

  1. Hydrodynamic Lubrication
  2. Mixed Lubrication
  3. Boundary Lubrication
  4. Elastohydrodynamic Lubrication

So, the thickness of the oil, determines its coefficient of friction. And, defines four distinct regions of Lubrication.

1. Hydrodynamic Lubricants And Oils

So, engine bearings and pistons mostly operate in, the “Hydrodynamic Lubrication” region. Where, a thick oil film, separates the moving metal surfaces. As a result, there is no chance of them, coming into contact.

2. Mixed Lubrication

When the pistons are momentarily stationary, the layer of oil, can be similar in thickness, to the surface roughness. In this “Mixed Lubrication” region, the metal surfaces, intermittently, come into direct contact.

3. Boundary Lubrication

If the thickness of the oil film, is smaller than the surface roughness. Then, the metal surfaces, rub together repeatedly. Consequently, contact between, the cams and the tappets in the valve train, span the mixed and boundary regions.

4. Elastohydrodynamic, Lubricants And Oils

“Elastohydrodynamic Lubrication” occurs under high loads. Here, the pressure developed in the lubricant, is sufficiently high, to elastically deform the metal surfaces. This happens because, the viscosity of these fluids, increases significantly, as the pressure rises. The valves and the piston rings, occasionally operate in this region.

Finally, it’s the additives added to an engine oil, that give it its qualities, to help with its performance.

Choose Your Lubricants And Oils Help Topic Below

Oil Consumption Has Many Causes, But, Worn Bearings Add To It

Engine Oil Additives – Seems To Be, The Elephant In The Closet

Fuel Wash – What is it – Check If You Have It – Common Causes

Engine Oil Consumption, Is On The Rise, Where It Go’s And Why

Fuel Getting Into Engine Oil – Learn The Cause, Effect And The Fix

Thank You !