Viscosity grades of motor oil

Motor oil is a extremely useful to maintain life of a motor in the engine.However there are different types of oil for different engine that serve their own purpose.So oils should be chosen carefully depending on their purpose and need.Factor that separate oils from each other is their viscosity. Different oils show different viscosity.Soinorder to measure viscosity of

oil is rated into different grades depending on its viscosity.

Grades of viscosity of motor oil:

Oils are thickened as they get thin when heated.Thin one flow easily to protect the engine from the damage.Oil should be iso certified which guarantees its long lasting performance.ISO grades available for oil are 22,32,46,68,100,150,220,320,460.

There are overall 11 viscosity grades which are 0W,5W,10W,15W,20W,25W,20,

30,40,50,60.According to the USA grading this numbers are considered in weight.Single grade motor oils are called as straight -weight oils.usually  original viscosity grades are mono grades.They provide lubrication too.

Types of grading:grading method varies from country to country.Most preferable system is chosen by the various countries.

Grading can be stated as:

1)Single grade :it is defined by SAE  J300 which does not include polymeric viscosity index improver.It includes 11 viscosity grades as mentioned before which are 0W,5W,10W,15W,20W,25W,20,30,40,50

60.For single non winter grade oils kinetic viscosity is 100 degree Celsius.word W is referred to the weight.However SAE grades are 20,30,40,a minimum viscosity is measured at the temperature of 100 degree Celsius.Grades increase with the increase in viscosity.

2)Multigrade:Differences in viscosity in single grade system are wide in most vehicles.Viscosity of oil is high in cold weather while it reduces on operation of

engine.SAEdesigned Multigrade system for two different viscosity grades.This grading system differentiate between oils to used in hot and cold weather.This systems clears limitations caused by

Single grade system.for example 20W-20.

Conclusion:

Few points to be note about motor oil grading are as follows:

1)Grading of oils is done on bases their viscosity (ability of oil to flow ) which should be thinner for its better quality and

Performance.

2)Proper oil should be use considering weather,vehicle and purpose served by the motor.It is better to have a expert opinion.

3)High quality oil serves better service and longer life of a vehicle so wise choice is necessary in selection of oil.

4)Suitable grade should be used in the vehicle considering the tendency of the motor in order to make sure about the purpose including viscosity.

5)Oils should be replaced when they loose ability to get thinner and it’s viscosity gets compromised after its  stated usage and time.

6)Oil viscosity grading differs from country to country.Soit always matters when and which viscosity grade we are using.