Another engine oil post!

[jacksdad63]

Hi there, don't panic, I'm not asking the usual...

Just a post about oil VI, Viscosity Index, something I have never in very many years looked at   

I serviced my 1100RT, and chose Castrol Power 1 4T, in 15W50 flavour.  I have since learnt it has a VI of 146. Now this is very good oil, without doubt, and it is 50 weight so nice and thick, right?

Sort of...

What I should have used is Castrol Power 1 Racing, 10W40. Now, I assumed this was 'thinner' than my choice, but!

The latter has a VI of 164!  

My basic understanding is that the higher VI means that this oil 'sticks' better, as the engine temperature rises, doesn't  break down as much as a lower VI oil.

The air cooled Boxer can get rather hot as we know, so next oil change I'll got for the 10W40 grade, as the higher VI will be better when things get heated. 

The VI rating, amongst more tecchy stuff isn't shown on the carton, I had to head online and look for the technucal sheets, bit of a hassle to start with but soon worked out.

Comments please!  

 

[jacksdad63]

Her's an example of what to search for:

 

EUR_Val_4TSyn_10W40_MCO_EN.pdf - DocuSign CLM (springcm.com)

[Camhead64]

18 hours ago, jacksdad63 said:

Hi there, don't panic, I'm not asking the usual...

Just a post about oil VI, Viscosity Index, something I have never in very many years looked at   

I serviced my 1100RT, and chose Castrol Power 1 4T, in 15W50 flavour.  I have since learnt it has a VI of 146. Now this is very good oil, without doubt, and it is 50 weight so nice and thick, right?

Sort of...

What I should have used is Castrol Power 1 Racing, 10W40. Now, I assumed this was 'thinner' than my choice, but!

The latter has a VI of 164!  

My basic understanding is that the higher VI means that this oil 'sticks' better, as the engine temperature rises, doesn't  break down as much as a lower VI oil.

The air cooled Boxer can get rather hot as we know, so next oil change I'll got for the 10W40 grade, as the higher VI will be better when things get heated. 

The VI rating, amongst more tecchy stuff isn't shown on the carton, I had to head online and look for the technucal sheets, bit of a hassle to start with but soon worked out.

Comments please!  

 

If the manufacturer says 15w50, use it if they want 10w40 use it. Viscosity Index is not actual viscosity and has nothing to do with "sticks better" it only the relationship between an oils viscosity and the temperature. The viscosity index of a lubricant is determined by measuring the kinematic viscosity at 40°C and 100°C. These measurements are then compared to the results of two reference oils. So what the difference implies is that over that temperature range the 10w40 changes viscosity slightly less than the 15w50, but both are still 40 weight and 50 weight at 100c or would have never been graded as such.  Don't overthink this, bottom line is the design engineering department and lubricant manufacturers have worked together to develop lubricants and make service recommendations that protect your engine under all but very extreme conditions if you purchase quality products (Castrol or other Name Brands) and follow service intervals.

 

If you want a good lesson in engine oil and how its made, engineered, and works, check out https://www.youtube.com/watch?v=-ZYSrLI34FA this you tube video and the other three in the series. May answer some of your questions.

 

Edited July 7, 2023 by NewportCycle
Corrected

[dirtrider]

21 hours ago, jacksdad63 said:

Hi there, don't panic, I'm not asking the usual...

Just a post about oil VI, Viscosity Index, something I have never in very many years looked at   

I serviced my 1100RT, and chose Castrol Power 1 4T, in 15W50 flavour.  I have since learnt it has a VI of 146. Now this is very good oil, without doubt, and it is 50 weight so nice and thick, right?

Sort of...

What I should have used is Castrol Power 1 Racing, 10W40. Now, I assumed this was 'thinner' than my choice, but!

The latter has a VI of 164!  

My basic understanding is that the higher VI means that this oil 'sticks' better, as the engine temperature rises, doesn't  break down as much as a lower VI oil.

The air cooled Boxer can get rather hot as we know, so next oil change I'll got for the 10W40 grade, as the higher VI will be better when things get heated. 

The VI rating, amongst more tecchy stuff isn't shown on the carton, I had to head online and look for the technucal sheets, bit of a hassle to start with but soon worked out.

Comments please!  

 

Morning  jacksdad63

 

If you are using good quality synthetic oil then the oil's Viscosity Index will not be a problem (almost all the uplevel synthetic oils have very good VI properties). It's some of the lower quality conventional oils that can have marginal VI properties. Especially after they are in use for a while & start to shear).

 

When it comes to oil "thickness" just keep in mind that oil never gets thicker as it heats up (within normal working temperatures). 

 

15w40 oil is basically 15 weight oil that doesn't get any thinner than 40 weight would at  100°C.

 

20w40 oil is basically 20 weight oil that doesn't get any thinner than 40 weight would at  100°C.

 

15w50 oil is basically 15 weight oil that doesn't get any thinner than 50 weight would at  100°C.

 

If oil VI (or BMW suggested viscosity) was an issue for the BMW 1100/1150 boxer engines then you would be reading about all the engine failures all over the internet. BMW 1100/1150 motorcycles had their share of problems but engine life was not one of them. You never hear of BMW 1100/1150 engine failure that was caused by use of BMW suggested oil type & viscosity. 

 

Just keep in mind the oil in the BMW 1100/1150 boxer is also the coolant for the hot parts of the cylinder head so you need an oil that carries that heat away into the oil cooler. (BMW figures that into their oil suggestion)

 

The other thing to keep in mind is the oil filtration part, thick oil can not flow through the oil filter easily so oil that is too thick when cold (or even somewhat warm) will not want to flow through the oil filter element so that forces the oil-bypass valve to open allowing oil to by-pass the oil filter (especially when the oil flow increases at higher RPM's) 

 

One thing to think about is the oil's additive package, at one time BMW had a service bulletin on not using SJ & above oils due to lower ZDDP content. This was long ago when the ZDDP content was just starting to be lowered due to possible catalytic converter damage.  

 

There could be some truth to that bulletin but I'm not sure it was ever much of a real  issue in the BMW 1100/1150 boxer bikes. My guess is that bulletin was based on some extensive Porsche oil testing in their Boxer engines that showed a possible problem with lower ZDDP type oils.  

 

The upside to the ZDDP thing is that that it is mainly lowered considerably in modern automotive motor oils like the 5w20, 10w30, 0wxx oils. Seeing as the 15w50 & 20w50 is not used in modern automobiles that oil has a better chance of having a higher ZDDP content but this not a given & for some modern 15w50  20w50 oils (finding that info can be difficult) 

 

Personally I never use anything labeled RACING in a street motorcycle unless I fully check the specifications out, the good news is the term "racing" , when it comes to oil, is usually just a marketing ploy. Real racing oil seldom contains long term additives for acid reduction, & other long term additive requirements as racing oil is usually a one-race use type thing then it gets changed.  But it sounds like better oil as it says "RACING" on the bottle so that sells oil to the uninformed.  

 

 

 

 

 

 

 

 

 

 

 

 

 

[Hosstage]

21 hours ago, jacksdad63 said:

Hi there, don't panic, I'm not asking the usual...

 

2 hours ago, NewportCycle said:

Don't overthink this

 

That.

[Lowndes]

Another "oil issue" to consider is synthetic vs mineral (or dinosaur) oil.  I had several oil weeps - not big enough to call a leak - with synthetic oil in my older oilhead bikes.  Worn and hardened seals, plus the surface-wicking ability of the synthetic oils made me go back to dinosaur oils for the engine, trans, and FD.  Just be aware of this small issue.

[Mike279]

The basics of oil.  Oil rating that have a W(winter) in them as 10W- indicate that the oil was tested at 0F(-17C) degrees and meets the test requirements for cold starting.  Important for those of us that see low temperatures a large part of the year.  The second number will give you the oils properties at the upper test temperature of 210F(100C) degrees.  Yup, don't overthink this, just buy the recommended oil and change it when needed. 

[jacksdad63]

Castrol specify the Power 1 Racing 10W40 for the 1100, not 20W50. 

I assumed the 50W oil would be best but apparantly thats not the case. Putoline make a Boxer full synthetic 15W50 oil,  and say i gives amazing wet clutch grip...

I'm going to change to the Castrol 10W40 next time, because its the one they recommend and its got a high VI. I use this same oil in my Kawasaki ZZR1200, as its also JASO MA2 rated. 

I do agree with the theory that changing the oil on a regular basis is the most important thing, using a top quality synthetic oil: the Boxer lump is a bit of an old tractor unit after all...

 

[jacksdad63]

interesting:

 

[dirtrider]

Quote

Interesting

Evening jacksdad63

 

It seems like that is more of a test of the oil pressure regulator valve than useful oil info.  

[dirtrider]

15 hours ago, jacksdad63 said:

Castrol specify the Power 1 Racing 10W40 for the 1100, not 20W50. 

I assumed the 50W oil would be best but apparantly thats not the case. Putoline make a Boxer full synthetic 15W50 oil,  and say i gives amazing wet clutch grip...

I'm going to change to the Castrol 10W40 next time, because its the one they recommend and its got a high VI. I use this same oil in my Kawasaki ZZR1200, as its also JASO MA2 rated. 

I do agree with the theory that changing the oil on a regular basis is the most important thing, using a top quality synthetic oil: the Boxer lump is a bit of an old tractor unit after all...

 

Evening jacksdad63

 

Is that recommendation for the BMW 1100 K bike not the 1100 R (boxer) bike. Most 1100/1150 (Boxer) riders use either the 20w50 or 15w50 unless starting & riding in fairly cold ambient conditions.

[jacksdad63]

Putoline make a Boxer oil then say its great with wet clutches! Its a bit expensive as well.

I just went for the Castrol 20W50 as I like the brand, no other reason, and then looked up what they recommend: 10W40

I agree with your comment on 'racing' oil, always sounds a bit of ad speak! like I said though, I do like Castrol and their Power 1 Racing is specified for the ZZR1200. The Jaso MA2 tells us its made for wet clutches, but any decent oil made for bikes should meet this requirement and of course it still works in the  few dry  clutch bikes like Boxers. 

Modern oils are so complex its hard to find the one thats best for your bike, and it seems everyone has a brand favourite, like I have! I'm  going to change to the higher VI spec for sure, that video I linked is pretty conclusive for me,  even though the first oil they test isn't very good, it still shows the benefits of the higher VI rating

 

Now,  what about additives? 

Wynns was the big one over here, not suitable in wet clutch or cars with combined engine/gearbox oil, but should we use any? This could get complicated .....

[dirtrider]

3 hours ago, jacksdad63 said:

Putoline make a Boxer oil then say its great with wet clutches! Its a bit expensive as well.

I just went for the Castrol 20W50 as I like the brand, no other reason, and then looked up what they recommend: 10W40

I agree with your comment on 'racing' oil, always sounds a bit of ad speak! like I said though, I do like Castrol and their Power 1 Racing is specified for the ZZR1200. The Jaso MA2 tells us its made for wet clutches, but any decent oil made for bikes should meet this requirement and of course it still works in the  few dry  clutch bikes like Boxers. 

Modern oils are so complex its hard to find the one thats best for your bike, and it seems everyone has a brand favourite, like I have! I'm  going to change to the higher VI spec for sure, that video I linked is pretty conclusive for me,  even though the first oil they test isn't very good, it still shows the benefits of the higher VI rating

 

Now,  what about additives? 

Wynns was the big one over here, not suitable in wet clutch or cars with combined engine/gearbox oil, but should we use any? This could get complicated .....

Morning   jacksdad63

 

Oil additives are a help for motorcycles, they lighten your wallet so that lightens the motorcycle.  Otherwise they are useless.  IF your oil needs an additive to supplement it then YOU ARE USING THE WRONG OIL!!!!!!!!!!!!! 

 

I don't understand all the wet clutch talk (it is meaningless for the BMW 1100/1150 boxer as the BMW 1100/1150 has a dry clutch). In fact having a dry clutch allows the use of some of the better motor oils as clutch slippage isn't even a remote concern. 

 

Same with the  Jaso MA2 rating, doesn't mean much on the BMW 1100/1150 boxer as it has a dry clutch.

 

Also, don't compare to water cooled motorcycles as the BMW 1100/1150 boxer is air/oil cooled so the engine internal tolerances are larger to account for the non-water cooling's more drastic parts expansion. 

 

It's your motorcycle so your choice in oil so you don't need to explain anything to us long time BMW boxer riders as we have a long history in using motor oil's that work exceptionally good through hot riding conditions & cold riding conditions. Motor oil hype & sketchy internet oil testing is more for entertainment than usable credible long term data. 

 

If the slick oil advertising  & non scientific on-line oil testing makes you want to use a particular oil then by all means use it. 

[Dave_in_TX]

21 minutes ago, dirtrider said:

 

 

Same with the  Jaso MA2 rating, doesn't mean much on the BMW boxer as it has a dry clutch.

 

For the less knowledgeable (not DR), the MA2 rating is valid for wethead boxers since they do have a wet clutch.

[Dave_in_TX]

From wikipedia:

" viscosity index (VI) is an arbitrary, unit-less measure of a fluid's change in viscosity relative to temperature change. It is mostly used to characterize the viscosity-temperature behavior of lubricating oils. The lower the VI, the more the viscosity is affected by changes in temperature."

While it may be valid to use it when comparing oils of same viscosity range (ex. one 10w40 to another 10w40) it shouldn't be used when the oils have a different range as the OP did.

[dirtrider]

15 minutes ago, Dave_in_TX said:

For the less knowledgeable (not DR), the MA2 rating is valid for wethead boxers since they do have a wet clutch.

Morning Dave

 

Good point, I purposely mentioned the 1100/1150 boxer but there could be some readers that don't catch that identifier. But just in case I also just added it to the Jaso  MA2 rating paragraph.