Dear all,
I am basically associated with industrial speciality lubricant sale in India, but recently developed good interest in automative and engine oil.
I would like to ask, in Indian(hot) condition, what is the effect on engine if somebody has switched over to 15W40 in place of 20W40 and 15W40 in place of SAE 40 grade oil respectively.
Regards

Dear Gentleman,

I would like to know you belong to which place in india and operating with which company.may be we can talk over the phone.

SKC

My personal email i.d is dctex04@indiatimes.com.
I am located in Rajasthan area and we may start communicating via email.
Thanks N Regards
Dipen

Dipen,

Modern energy efficient oils today are multigrades and most popular oils are 15w/40 or thereabouts. Till a few years ago 20w/40 viscometrics was very popular but to meet the API Energy Efficient catergory most lube manufacturers have switched to 15w/40.It applies to both Petrol (SI) or Diesel (DC) engines.

In India we have sold millions of litres of CF4 grade Castrol RX Super Plus a 15w/40 oil without any problems; whether used in the coldest of Kashmir to the hottest South Indian town. Major lube companies ensure that oils deliver performance in all conditions.

Trust this answers your query.

Hussam Adeni

Dipen

It also depends on whether you are talking about On highway or Off Highway equipments.

In the case of On Highway equipments most of the OEMs have upgraded their engine designs in terms of power ,efficiency etc.... which require better lubricants.

Therefore use of a 15W-40 Oil would be beneficial than 20W-40 because it is packed with extra masala in it. Hope your understand.

In case you require more details you can contact me at frankyxavier@yahoo.co.uk.

Dear Dipen,

Your message is posted some Two Months back.

I happened to join the forum recently; I thought I might as well take this opportunity to share my experiences on the subject.

First and foremost, there is no set/affirmed condition of temperature for automotive Engine oil or gear oil for that matter (in response to your statement “Indian (hot) condition.)

The selection of automotive engine oil for a particular vehicular application depends on various criteria, ambient temperature being an important one.

Mono grade oils like Viscosity grade 40 as mentioned by you conform to a particular temperature –viscosity range under SAE classification and fall under summer grade. Other grades under summer grades are SAE 20, 30, 50, 60 etc. Similarly, “W” denotes the grades which refer to winter grades and are the viscosity grades of oils which will maintain the flow of oil in winter conditions at the particular temperature range under which they fall. These grades are mainly 0W, 5W, and 10W, 15 W, 20 W and 25 W. The winter grade of oils classifies Low temperature viscosities i.e. cranking and pumping viscosities covering temperature ranges from -5 degrees Celsius to -40 Degrees Celsius.

Thus speaking in simpler and layman terms for winter grades, lower the ambient temperature, usage of lower winter grade will ensure that the oil will maintain its viscosity therefore flowability during cranking and will pump with ease through oil pump at the specified range of lower temperature without damaging the engine during cold start. But since the winter grade oils have a very low viscosity, as the temperature of the oil rises during operation, this grade will tend to become even less thinner thereby leading to rupture of the protective film and engine damage. To overcome this problem, the winter grades are blended in right proportion at manufacturing stage with the summer grades which conform to high temperature viscosity range thereby yielding the multigrade oil.

The following points may give a brief idea:

• A multigrade oil is combination of two viscosity grades a) a winter Grade b) a summer grade
• The winter grade is a low viscosity grade of oil classified from 0W to 25 W under SAE J 300 classification which determines the ability of each grade to operate/maintain flowability and pumpability at different temperatures, 0W being the lowest temperature range grade and 25 W the highest range grade classifying cranking temperatures from -30 degrees C for 0W to -5 Degrees for 25 W and pumping viscosity of 60000 cP from -40 Degrees C to -15 Degrees C for 25 W.
• Similarly the summer grades 20, 30, 40, 50 and 60 fall under a particular range of viscosity under 100 degrees Celsius.
• Thus the selection of multigrade oil will depend upon the lowest ambient temperature engine oil is likely to witness during cold cranking.
• In order to understand the effect in change of parameters on converting from 20W40 to 15W40 lets see the temp range under which they fall:

a. 20W : Cranking cP max at Temp: 4500 at -10 degrees C
b. 20W : Pumping cP with no yield stress at Temp= 60000 at -20
c. 15 W : Cranking cP max at Temp: 3500 at -15 degrees C
d. 15W : Pumping cP with no yield stress at Temp= 60000 at -25

• Thus by lowering the winter grade, we have actually molded the engine oil to operate effectively in colder conditions.

Coming back to the change in grade from 20W40 to 15 W 40…….in Indian hot conditions:

• Are u referring to usage of the MG engine oil in vehicles at places where mercury dips below -10 up to -15 Degrees C?

If the answer is yes, go ahead and immediately change to 15W40...u may avert a serious damage to your engine during cold start.

• Are u in an area where the mercury does not dip below -10 degrees?

Keep using 20W40.

• If you operate the vehicle in places where the engine oil is not subject to wide temperature variances, keep using the Mono grade i.e. 40 viscosity. But that doesn’t give leverage for the oil to maintain flowability under varied changes in ambient temperatures.

In fact the vehicles which ply under variable temperature conditions moving from different ambients in different seasons should make use of the multigrade oils to take care of factors as explained above.

And moreover as the winter grade of the oil keeps going lower, the price of the oil keeps going higher. Therefore if 20W40 is able to take care of the operational temperature range why pay more for 15W40 oil? And if the engine requires an oil to take care of sub zero temperatures during cold start, why change to monograde oil? Because the damage to the engine is going to be much more costly than the difference in cost of Mono grade and 15W40.


GOTCHA…..Thanx

Sandy

Dear Hussein Adeni,

Quote

"Modern energy efficient oils today are multigrades and most popular oils are 15w/40 or thereabouts. Till a few years ago 20w/40 viscometrics was very popular but to meet the API Energy Efficient catergory most lube manufacturers have switched to 15w/40.It applies to both Petrol (SI) or Diesel (DC) engines."

Unquote-

Can u please elaborate on the API energy efficient Category? Whats' viscometrix gotta do with energy efficiency? can u please submit any relevent data to prove that viscometrix like 15w40 in place of 20w40 leads to savings in energy i.e. either decreased lube/fuel consumption or enhanced power output with same consumption?

Regards

Sandy

Hussam Sorry...please read your name corrected as Hussam instead of Hussein

Just a message to Franky Zavier - your quote "Therefore use of a 15W-40 Oil would be beneficial than 20W-40 because it is packed with extra masala in it" is incorrect.

The viscosity grade is no measure of the overall performance of the oil. One can have a 0W-40, 5W-40, 15W-40 grade of oil, all with the same additive package meeting the same specs. The viscosity grade is met by adjustment of the base oils and/or the use of viscosity modifiers.

Sandy,

I agree with you. The viscometrics (SAE numbers) does impact the performance of the engine oils. The additive package and performance levels through meeting API SH or CI etc decide how good or bad the engine will perform.

Hussam Adeni

Sandy,

Over the past decade there was a shift from the popular 20w/40 viscosity to 15w/40. During the same period engine metallurgy also changed from ferrous to mixture of aluminium and its alloys. The engines began to run faster and hotter. This made oil companies shift to lower viscosities and they joined the bandwagon of energy efficient and fuel efficient oils. Theoritically quite possible too.

I am confident this is not a Marketing gimmick and all oil companies will able to prove the newer oils are energy efficient and thereby fuel efficient as well. API themselves, licence this energy conservation by permitting a "Energy efficent donut" or blip on such products.

Hussam Adeni

good explanation for the beginners from Sandy
I did learn some thing.
regards
Arupanjan

Sandy,
Some of the energy produced by the engine is used by itself. For example, electric generator, water pump, steering pump, air compresor, overhead cams and of course oil pump.
Move the oil trough the engine requires some energy. Fluids with less flow restriction will reduce parts in movement efforts, which means less energy.
I am not an expert in this area, but this is my understanding in how an especific lubricant can be name "energy efficient"

Luis,

I agree with you. What we know is possible in theory, is rightly identified and listed by you.

Thanks for your inputs.

Hussam Adeni

Dear Hussam,

The point is whether or not some studies have been carried out to prove that use of a lower viscometrix oil in place of a higher range actually leads to savings in energy inputs in an engine thereby leading to savings in fuel costs. One has to appreciate that the user has to be satisfied on tangible benifits that he can derive out of changing the viscometrix and must be able to corelate it with cost savings, otherwise where is the change over justified?

If u have data or details of studies on this, Kindly share.

regards

Sandy deeds

Sandy,

SAE 20W-40 & SAE 40 oils available in India is
of CD grade only.Since VI is less compared to
CF4 oils,CD oils will get oxidised,resulting in
higher viscosity and affecting the energy output.Use of adulterated fuels,unserviced fuel systems,Engines not in tune which results in
increased soot levels,elevated viscosity,excess
deposits formation all affects engine efficiency
Modern oils like CG4,CH4 oils keeps the engine
clean,thereby reducing wear/Friction....

Bala.

Bala Hi!

Is VI related to Oxidation value? I really dont think so? Oxidation of the oil will depend on the quality of the base oil at refining stage, and the operating conditions i.e. severity of heat (temperature), moisture and the quality of fuel.

Under the same operating conditions u mean to say that a high VI oil will resist oxidation in a better way than a low VI oil?

I am of the opinion that VI of a oil will not control the levels of oxidation, it will only resist the change in its viscosity with temperature in a better way than a low VI oil as we all know.

Higher grade oils will definetly be better performing in terms of lower levels of soot, carbon laquer depositions because of better additive dosgaes and the rigourous bench tests that they have to pass..

Regards

Sandy deeds

Sandy,

Even under stressed and abnormal conditions oil
should able to provide better oil film protection.Less VI oils fails during high engine
blowby conditions,Localised hot spot,Engine Overheating,Fuel dilutions increases shear and
subsequent oxidation.I guess that all API test
bench conditions are not carried out with used and contaminated oils....

Regards

Bala.

Bala,

What you say is correct, API tests are not carried out on used engine oils. The point is that base oils with dosages of "re-refined base oils" can be tested to meet the API performance levels.

If the results are within the tolerable limits of API performance levels of virgins base oils, it should be acceptable.

Hussam Adeni

Hussam Adeni