Basics on lubricants

COMPOSITION OF OIL

BASE OIL + ADDITIVES

• Additive is a substance added to base oil to enhance or prolong its performance

Why a plain Mineral oil won’t suffice ???

External Environment

Friction Wear

What The Oil Must Do- Lubricate -

Base Oil

Antioxidants, antifoamAnti-wear

Dispersants

Detergents

VI Improvers

Ingredients of an Engine Oil

Base oils : 70 – 90 %

Types : Mineral and Synthetic

Additives :

Performance chemicals blended with base stocks to Boost or Suppress or add new property to the base oil

What are Additives ???

Lubricant additives

DETERGENTS

Function : • high temperature deposit control • Neutralize acids• rust inhibitor• e .g. Sulphonates , Phenates , Salicylates of Ca, Mg and

other metals

Lubricant additives

DISPERSANTS

Functions• Controls engine sludge• Prevents soot agglomeration and oil

thickening• Controls engine varnish

e.gSuccinimides (mono,bis) , manich type etc

Lubricant additives :Antioxidant and antiwear additives

Antioxidants :–Controls oxidative decomposition of oil–Minimizes oil thickening

e.g. Hindered phenols , Dithiophosphates etc

Antiwear additives

-reduces wear between contacting surfaces e.g. Thio phosphates ( ZDP) , Sulphurised olefins etc

Lubricant additives :VI improver & PPD

• VII : • Reduces the rate of change of oils viscosity with

temperature.• e.g. PMA , PIB , OCP etc

• PPDs :• Lowers pour point• Prevents interlocking • e.g.:PMAs , Poly alkyl fumarates

Lubricant additives : FMs

• Function : Reduces friction between contacting surfaces

• e.g. : fatty acid compounds with polar ends , Graphite MoS2 dispersions

• Other additives :

• Corrosion inhibitors , rust inhibitors , Metal deactivators , anti foams etc

Lubrication Points in an Engine

Camwear

Valve Train Wear

Cylinder Bore Polish

Sludge

Piston Deposits

Piston Rings Sticking

Filter Choking

Bearing Corrosion

Oil Thickening

COMPOSITION OF OIL

ADDITIVES• DETERGENTS• DISPERSANTS• CORROSION INHIBITORS• ANTIWEAR ADDITIVES• VISCOSITY IMPROVER• POUR POINT DEPRESSANTS• EXTREME PRESSURE (EP) ADDITIVES

DETERGENT

• A substance added to a fuel or lubricant to keep engine parts clean. In engine oil formulations, the detergents most commonly used are metallic soaps with a reserve of basicity to neutralise acids formed during combustion.

DISPERSANT

• An additive which helps keep solid contaminants in a crankcase oil in colloidal suspension, preventing sludge and varnish deposits on engine parts. Usually non-metallic (ashless), and used in combination with detergents.

CORROSION INHIBITOR

• Additive for protecting metal surfaces from chemical attack by water or other contaminants.

ANTI-WEAR ADDITIVE

• Additives or their reaction products which form thin, tenacious films on highly loaded parts to prevent metal-to-metal contact.

VISCOSITY IMPROVER

• Lubricant additive, usually a high molecular weight polymer, that reduces the tendency of an oil's viscosity to change with temperature.

POUR POINT DEPRESSANT

• Additive used to lower the pour point or low temperature fluidity of a petroleum product.

EP ADDITIVE

• Lubricant additive that prevents sliding metal surfaces from seizing under conditions of extreme pressure.

API Classifications

• CA• CB• CC• CD• CD II• CE• CF• CF 2

C - COMPRESSION IGNITION• Light Duty• From 1949 moderate duty• Moderate to severe duty• Severe duty turbo / supercharged• Detroit Diesel• From 1984 - severe duty turbocharged - SHPD• To replace CD• From 1993 - Detroit Diesel - to replace CD II

API Classifications

• CF 4

• CG 4

• High performance diesel engine oil - oil consumption control

• Severe duty diesel engine oil - to meet exhaust emission standards

US Military Specifications

• MIL-L-2104A From 1940• MIL-L-2104B From 1958• MIL-L-2104C From 1970, similar to

combination of API CD & SD

• MIL-L-2104D From 1983, similar to combination of

API CD & SE

US Military Specifications

• MIL-L-2104E From 1990, will meet requirements of

API SF

• MIL-L-2104F From 1994, contains more advanced

API specifications

ROLE OF ENGINE OIL

• LUBRICATION

• CLEANING

• PROTECTION

• COOLING

• SEALING

LUBRICATION

• OIL FORCES ITSELF BETWEEN MOVING METAL SURFACES AND KEEPS THEM APART

CLEANING

• COMBUSTION ENGINE PRODUCE CONTAMINANTS LIKE VARNISH & LACQUERS

• DETERGENTS CLEAN AWAY HIGH TEMPERATURE DEPOSITS

• DISPERSENTS KEEP INSOLUBLES SUSPENDED

PROTECTION

• PROVIDES A DURABLE FILM PROTECTING METAL PARTS FROM WATER & ACIDS FORMED DURING COMBUSTION PROCESS

COOLING

• CIRCULATING OIL CARRIES HEAT AWAY FROM HIGH TEMPERATURE AREAS

SEALING

• TO PREVENT BLOW-BY, OIL ACTS AS SECONDARY SEALANT

Viscocity factors

ADVANTAGES OF MULTIGRADE OILS

• Seasonal Oil Changes Eliminated• Easier Starting Plus Good Anti Wear Performance• Pump ability• Reduced Oil Consumption• Reduced Fuel Consumption• Better Bearing Lubrication• Engine Cleanliness

Gear Oil SpecificationsAPI Type Application

GL-1 Straight mineral oil

Automotive manual truck tranmissions (needing no EP additives)

GL-2 Contains friction modifiers-fatty material

Automotive worm gear drives, used where GL-1 not sufficient

GL-3 Contains mild EP additive

Moderately severe manual transmissions and spiral bevel axles (FWD)

GL-4 Contains EP additive usually 50% of GL-5

Hypoid gears in manual transmissions and transfer cases, high speed low torque and low speed high torque operating conditions

GL-5 High EP additive level

Hypoid gears in manual transmissions and rear axles - high speed shock loads,high speed low torque and low speed high torque operating conditions.