Somebody take me to oil school

[Ozwynn]

I’m running Lucas 20w50 full synthetic V twin oil (because this is what was a available) in my Royal Enfield. The dealership, which is an Indian dealership, only uses Schafer 20w-50. The owners manual calls for full synthetic 10w50 motorcycle oil. The full synthetic 10w-50 is not readily available to me, has to be ordered….
What I have readily available in full synthetic motorcycle oil is (pick your flavor) 10w-40, 20w-50, and Rotella T-6 15w40 and 5w40. I understand the small number. What I don’t understand is the big number. I’ve always just used the weight specified by the owners manual.

since I will be riding in cold weather I want to use either a 5wXX or even a 0wXX oil….. I just know if it absolutely has to be 50 or can I run 40….

so can anyone explain what the big numbers mean? I asked at the Royal Enfield Forum and it started a 7 page death match on what the best brands are but I didn’t get my question answered.

 

[pjtoledo]

search "bob the oil guy'

lots of info there

 

[ericbphoto]

I asked at the Royal Enfield Forum and it started a 7 page death match on what the best brands are but I didn’t get my question answered.

Unfortunately, oil threads seem to do almost the same thing here. I won't try to answer cuz I just plain old "don't know".

Good luck.

 

[pjtoledo]

does the Royal Enfield manual give a specification or rating for the oil? not just the weight, there are separate specs and ratings for oils.

 

[Ozwynn]

does the Royal Enfield manual give a specification or rating for the oil? not just the weight, there are separate specs and ratings for oils.

It has to be wet clutch oil. And I’m not shopping a brand (even though REUK recommends Silkolene, RENA has no recommendation other than synthetic wet clutch approved) but when I asked if I could use Xw40 or if it had to be Xw50 it started a war between the UK/commonwealth guys and the rest of the world…. I think I might be the cause of WW3.
If the only reason it needs to be Xw50 is because of high Ambient temps then I should be good with Xw40 because it never gets to 48 degrees C here in southern Michigan. But if it need the extra cushion to fill a gap in the gear box or cylinders or valve train (not likely because I have roller rockers) then I want to know if Xw40 is good enough because in a 50 multi grade I can only get 20w50 and from what I understand most of the engine wear is done in the first 10 minutes after start up so the lower 10, 5, or 0 is of more importance to me. But I can’t get a direct answer from the forum, from the manufacture, or from the owners manual.
All of them seem to assume I am stupid, try to explain it to me on a kindergarten level, and just tell me to use what they say (which I would if it was readily available, but I live in Harley country so everything motorcycle revolves around with Harleys or sport bikes) without explaining why I have to use that grade…

 

[pjtoledo]

Southern Michigan?

I was out joy riding driving between Clinton, Cambridge Junction and Hudson today.

wet clutch? don't some forklifts use a wet clutch? maybe an industrial supplier?
take a look at the specs on the Schafer 20-50 package and compare/go shopping.
the link below has the Harley specs this oil meets.

"Schaeffer" 20w 50

Schaeffer Extreme V-Twin Synthetic Plus Racing Oil - Schaeffer Oil Products (jdindustrialsupply.com)

 

[fastpakr]

The wet clutch rating is (or at least used to be) indicated by JASO-MA) on the oil label. Rotella T6 was always a great option in that regard.

 

[1990RangerinSK]

Here's the simple explanation. 20W50 refers to how thick the oil is. More importantly, it denotes that the oil is multi-viscosity. It has an additive that, below 32*, it is thinner (20 weight), but at operating temperature, it is 50 weight, or it's normal thickness (or maybe I have it backwards, maybe it's normal thickness is 20, and the additive causes it to thicken up at operating temperature).

The problem is that oil, as it gets cold, thickens. The thicker the oil is, the less effective it is at lubricating moving parts.

Does that help? Is that the explanation that you need? Or did I fail?

 

[Ozwynn]

It’s roughly the same explaination I usually get. You did good at that part. I’m looking for the why I have to use 50 instead of 40. I know that Xw50 is used in V Twins because the rear cylinder runs hotter than the front. I have a parallel twin. My cylinders revive equal cooling and I have an impressively over sized oil cooler for a 650cc. The Xw50 makes sense for India where the bike is manufactured because of high ambient temps. But it just doesn’t get that hot here…. If it’s because of a sloppy gear box and sub par tolerances in the engine then Xw50 is not needed because the 650’s gearbox is sport bike precision and so is the valve train and the clutch only cares about friction modifiers… it doesn’t care about the grade…. I could run ATF +4 in the gear box if it didn’t share its oil supply with the engine.


Elkhart Indian motorcycles uses Schaefer 20w50 because that’s what they use in all the bikes they service…. Because they mostly service Indians and Harleys….

 

[rubydist]

As mentioned earlier, the first number (i.e. 20W) refers to the low temperature viscosity, and the second number (i.e. 50) refers to the operating temperature viscosity.

according to my SAE books:
0W has a max cranking viscosity of 3250 cP at -30C and a max pumping viscosity of 30k cP at -35C
5W has a max cranking viscosity of 3500 cP at -25C and a max pumping viscosity of 30k cP at -30C
10W has a max cranking viscosity of 3500 cP at -20C and a max pumping viscosity of 30k cP at-25C
15W has a max cranking viscosity of 3500 cP at -15C and a max pumping viscosity of 30k cP at -20C
20W has a max cranking viscosity of 4500 cP at -10C and a max pumping viscosity of 30k cP at -15C
25W has a max cranking viscosity of 6000 cP at -5C and a max pumping viscosity of 30k cP at -10C

20 has a kinematic viscosity of between 5.6 and 9.3 cSt at 100C
30 has a kinematic viscosity of between 9.3 and 12.5 cSt at 100C
40 has a kinematic viscosity of between 12.5 and 16.3 cSt at 100C
50 has a kinematic viscosity of between 16.3 and 21.9 cSt at 100C
60 has a kinematic viscosity of between 21.9 and 26.1 cSt at 100C

For those who need a quick refresher, -40C = -40F, 0C = 32F, 100C = 212F

OP, since I highly doubt you will be riding your bike at temps below freezing, the difference between 10W and 20W is not going to be important to you. However, the difference between 40 and 50 is significant. If your spec is for a 50 weight oil, I would not put a 40 weight oil in there even in the winter.

 

[sgtsandman]

One has to be careful with lubrication specs when dealing with air cooled engines and wet clutches.

Unless you can get hard data, preferably from the manufacturer or a reputable source that knows your motorcycle very well, I would not deviate.