Engine Oils

[catchdoon]

this is my first four stroker. the last one i rode is mahindra flyte owned by my uncle. i still ride it. but this vehicle ( piaggio vespa) is my own and waited for it for the last two years to get it launched in India.
the service centre guy says my warranty would be voided if i used any other grade!
i just hope 5w40 will not degrade the engine life. yet to get it serviced. still 400 on the odo. trying not to use it for more than 10 kms at a time. don't want the engine to get overheated.
does 5w follow the required viscosity index of 10w too at high temperatures ?

While describing Oil tolerance limits and their viscosity figures, the numbers 5w-40 have the following meaning:
5w represents a winter viscosity index generally measured at 0'C(in cSt) while the w40 represents the viscosity at 100'C!

The grades:
0w-40
5w-40
10w-40
15w-40
20w-40
will all have the SAME viscosity at 100'C or as you say Higher temperatures but will have different viscosity at lower temperatures, to be more specific at 0'C!

Likewise all the following grades(If some grades don't exist, just consider them as example):
15w-20
15w-30
15w-40
15w-50
will all have DIFFERENT viscosity at 100'c but same at 0'C

Look at the following link, the viscosity in centiStokes at different temperatures hope even further add up to your knowledge:

ISO Grade Oil Properties

[murlidhar]

While describing Oil tolerance limits and their viscosity figures, the numbers 5w-40 have the following meaning:
5w represents a winter viscosity index generally measured at 0'C(in cSt) while the w40 represents the viscosity at 100'C!

The grades:
0w-40
5w-40
10w-40
15w-40
20w-40
will all have the SAME viscosity at 100'C or as you say Higher temperatures but will have different viscosity at lower temperatures, to be more specific at 0'C!

Likewise all the following grades(If some grades don't exist, just consider them as example):
15w-20
15w-30
15w-40
15w-50
will all have DIFFERENT viscosity at 100'c but same at 0'C

Look at the following link, the viscosity in centiStokes at different temperatures hope even further add up to your knowledge:

ISO Grade Oil Properties

thanks a lot for the information
earlier i had a perception that 5w would have got too thin at higher temperatures nullifying the effect of a lubricant.
but isn't that the thinner oil the better flow and reaches faster to the engine when we start it? but as the temperature grows the viscosity increases making it a perfect lubricant in higher temperatures.
so practically isn't 5w60 the one and best oil for all four stroke engines in all conditions?

[catchdoon]

thanks a lot for the information
earlier i had a perception that 5w would have got too thin at higher temperatures nullifying the effect of a lubricant.
but isn't that the thinner oil the better flow and reaches faster to the engine when we start it? but as the temperature grows the viscosity increases making it a perfect lubricant in higher temperatures.
so practically isn't 5w60 the one and best oil for all four stroke engines in all conditions?

No U didn't get it. When a manufacturer says that your engine is recommended XXw-YY oil grade, then the YY is generally meant to be at 100'C which are in adverse conditions! Now using a w60 oil for a w40 recommended engine will be more sluggish at the temperature normally attained by the bike as the perfect viscosity will be attained by a w40 oil.

So using a much higher wYY oil grade will result in sluggishness, dampening the Engine performance and might as well not reach to the inner parts due to its high viscosity.

[Honda_CBF]

No U didn't get it. When a manufacturer says that your engine is recommended XXw-YY oil grade, then the YY is generally meant to be at 100'C which are in adverse conditions! Now using a w60 oil for a w40 recommended engine will be more sluggish at the temperature normally attained by the bike as the perfect viscosity will be attained by a w40 oil.

So using a much higher wYY oil grade will result in sluggishness, dampening the Engine performance and might as well not reach to the inner parts due to its high viscosity.

+1.
another thing is multi-grade oils are made by using a additive called Viscousity Index Improvers (VII's) which is not a lubricant but a polymer. Which easily gets destroyed. And wide range oils have them more. These additives gets distorted with use and oil starts loosing its high temperature rating. Thats why wide range oils are rare and some people dont like it.
Note: this VII thingy is not applicable to FS oils because they dont contain any VII or the content is very low.

[catchdoon]

+1.
another thing is multi-grade oils are made by using a additive called Viscousity Index Improvers (VII's) which is not a lubricant but a polymer. Which easily gets destroyed. And wide range oils have them more. These additives gets distorted with use and oil starts loosing its high temperature rating. Thats why wide range oils are rare and some people dont like it.
Note: this VII thingy is not applicable to FS oils because they dont contain any VII or the content is very low.

Missed on that. Thanks for adding that up

[murlidhar]

No U didn't get it. When a manufacturer says that your engine is recommended XXw-YY oil grade, then the YY is generally meant to be at 100'C which are in adverse conditions! Now using a w60 oil for a w40 recommended engine will be more sluggish at the temperature normally attained by the bike as the perfect viscosity will be attained by a w40 oil.

So using a much higher wYY oil grade will result in sluggishness, dampening the Engine performance and might as well not reach to the inner parts due to its high viscosity.

ah ok. will always stick to the company recommendations then.

[catchdoon]

ah ok. will always stick to the company recommendations then.

You should preferably use company recommended oil grades but the lower grade can be played with. In the Oil grade XXw-YY you can choose a sub XX grade i.e. if 20w is recommended can go for 15w or 10w, like in for winters. This will help in non sluggish starting in winters as at the temperature then, 10w/15w is going to be less viscous than 20w, thereby giving you hassle free starts in winter. Also there will be less engine wear and tear as the less viscous oil will flow with much ease in a stand-still bike.

[muztariq]

hey, nice discussions going on here..

If the company specifies xxWyy you can not only choose sub xx grades but also supra xx grades as per the climate you are living in.. Like in your case 5w40 for europe translated into 15w40 in India.. If enfield recommends 15w50 motul.. Anyone using 20w50 is not doing any harm to the engine.

The last thing to add up to your knowledge.
Its not just the sae grade that is important. The quality of oil is equally important.
A castrol 15w40 ss is poorer than a motul 20w40 mineral.. Quality matters a lot. Experiment more and more and then choose the oil that matches your riding style.. But going by the experience of many riders here.. Motul rules the w40 and w50 arena.

[gallifrey]

i would just like to ask a simple question on engine oils. i'm not so well versed in the concept ,so pardon me if it sounds a bit silly.

vehicle manufacturers specify a particular grade of engine oil to be used in their vehicles. they also say that if any other grade is used, performance may be affected.

last year, hero honda suddenly changed the engine oil for its vehicles from 20w40 to 10w30..they advise ppl not to use any other oil other than the recommended grade but they keep changing the grade arbitrarily.

[murlidhar]

i would just like to ask a simple question on engine oils. i'm not so well versed in the concept ,so pardon me if it sounds a bit silly.

vehicle manufacturers specify a particular grade of engine oil to be used in their vehicles. they also say that if any other grade is used, performance may be affected.

last year, hero honda suddenly changed the engine oil for its vehicles from 20w40 to 10w30..they advise ppl not to use any other oil other than the recommended grade but they keep changing the grade arbitrarily.

maybe the quality of engine components have changed and their research department found that the former grade is not anymore performing better than the later grade.
just a speculation.
i too have heard that HSMI has changed the grades for activa and other bikes.

[Krish1417]

What's the cost of Motul 7100 4T 10W40 oil?

[vrags]

What's the cost of Motul 7100 4T 10W40 oil?

650INR in JC Road, Bangalore. Not sure if its the same around other cities too.. And Motul 300V (15W50) costs 950INR.

[Rahulbarik]

I still didn't get my answer about petronas sprinta ss and fs... Why is this oil so under rated?

[murlidhar]

I still didn't get my answer about petronas sprinta ss and fs... Why is this oil so under rated?

haven't seen in the market at all.
can't comment about it.

[catchdoon]

I still didn't get my answer about petronas sprinta ss and fs... Why is this oil so under rated?

Who said it's under-rated? It is always person to person experience and if the permutations and Combinations falls wrong people say that an oil is bad!

Some fellow xBHPians themselves have used and liked it.