Why/how is motorcycle oil unique? Mobil 1 0w40 in my ATV?

JASO tests wet clutch friction, good. Is there only one type of material wet clutches use? What about surface area, engine output etc.? None of that I saw accounted for in their test.

Yes, the test is there but what happens if your clutch still slips on a particular JASO oil? Should one just ignore the slippage because the oil was JASO certified?

There is a member here that experienced that with JASO oil, switched to something else, not sure if it was JASO or not, and slippage stopped.

What sort of guarantee is there that JASO oil will not cause clutch slippage?
 
Begging the question. It's a thing.
JASO tests wet clutch friction, good. Is there only one type of material wet clutches use? What about surface area, engine output etc.? None of that I saw accounted for in their test.

Yes, the test is there but what happens if your clutch still slips on a particular JASO oil? Should one just ignore the slippage because the oil was JASO certified?

There is a member here that experienced that with JASO oil, switched to something else, not sure if it was JASO or not, and slippage stopped.

What sort of guarantee is there that JASO oil will not cause clutch slippage?
As I already stated: "If there's something I don't like about it, I'll try another brand."

And, too bad so many people spent so much time & invested in so much equipment to invent something so useless.
 
Show me a JASO wet clutch test, not an automatic transmission wet clutch test. Then we can discuss the mechanisms “many people” understand. Not sure who is that though. Is that “many people” on BITOG or somewhere else?
Last bullet in that article ... JASO T903 is for motorcycle wet clutches.

1669751994549.png
 
Last edited:
Yes, that’s the document for JASO. All they want is dynamic/static friction characteristics and stop time index. Nowhere do they state how these are obtained nor cite an SAE test for it or some other equivalent. Do you know how these are obtained? Does anyone else on BITOG? There are no units there just a range index. Do you know what the index represents?

You claim this is common knowledge on BITOG and the rest of internet, so I’m sure you can answer these simple questions.

View attachment 128476
It's a friction index. The "SAE #2 Clutch Friction Test" is one way to measure it.

See 4th bullet.

1669752821806.png
 
Last edited:
You are still yet to explain the mechanisms that impact wet clutches that apparently are common knowledge.
The "mechanism" that is being addressed is possible clutch slippage from oil that is too "slippery" for wet clutches. If the clutch starts slipping, even a little bit, eventually over time it will glaze and quickly go down hill from there.
 
LOL, missed it at the very end. Thanks for pointing this out. Although it only lists one of the three tests.
One of the 3 tests? That bullet refers to the friction tests requirements called out in JASO T903, so that means all 3 of the friction specs in JASO T903.
 
One of the 3 tests? That bullet refers to the friction tests requirements called out in JASO T903, so that means all 3 of the friction specs in JASO T903.
There is Dynamic Friction Characteristic Index (DFI), Static Friction Characteristic Index (SFI) and Stop Time Index (STI). SFI is done at low 300RPM speed, don't know about the other two, they may be done at high speed. That bullet specifically states in parenthesis "(high speed plate clutch)". Not sure why they would single that out.
The "mechanism" that is being addressed is possible clutch slippage from oil that is too "slippery" for wet clutches. If the clutch starts slipping, even a little bit, eventually over time it will glaze and quickly go down hill from there.

Yes, it's friction and that's it. The test is done on a generic clutch, no accounting for different clutch materials, surface areas or engine output. That spec may be fine for applications that call for it, but not all. However it is recommended blindly for all applications, even ones that are 30-40 year old.
But recommend a non energy conserving oil, but without JASO and that is seen as a problem. Their standard clearly states that an oil must also meet the API, ILSAC or ACEA "other than Energy Conserving". So while JASO eliminates some of the guess work, it adds nothing on its own that would be specific to motorcycles, like say clutch material deposit control, tighter shear control or high temp. thinning. Nope, nothing of that sort.


Capture.PNG
 
Well... yes. I guess we agree here. JASO MA/MB is all about clutch friction and slippage... I can only add, while maintaining usefulness as a motor oil.

Is that news?
 
Well... yes. I guess we agree here. JASO MA/MB is all about clutch friction and slippage... I can only add, while maintaining usefulness as a motor oil.

Is that news?
I don't think it's news as far as clutch slippage, however, reading various threads about the subject many seem to think that motorcycle oils are specifically formulated for motorcycles or that JASO is a clutch compatibility cert, (I guess causing slippage could be considered a compatibility problem), but compatibility usually means testing against most predominant variants. Sort of like coolants are tested against most used materials in various cooling systems in the industry.
I think I've seen some youtube videos about incompatible materials in non-JASO oils "impeding" themselves into clutch plates. There is probably more that I don't recall


So I truly think many don't realize that JASO cert, really boils down to oil friction.
 
What sort of guarantee is there that JASO oil will not cause clutch slippage?

JASO does not test oils to guarantee against slippage... JASO only
certifies oil... as of 2022 JASO has certified 1,458 oils which covers
virtually everything on the market including 0w oils that qualify as
Energy Conserving...

That is because Energy Conserving is not additive... its an API
mileage test that this "oil MAY result is an overall saving of fuel
in the vehicle fleet as a whole" there is nothing in the oil to
defeat a wet clutch....


219 0w30 Energy Release MB
223 0w30 Energy Release MB
225 0W30 Energy Release MA2
372 0w30 Honda Ultra G4 MA
380 0w30 Honda Ultra G4 MA
384 0w30 Honda HP4 MA
801 0w30 Motorex Power SYNT 4T MA2
1324 0w30 4CT-30 Wako MA
1333 0w30 4CT-30 Wako MA

227 0w40 Energy Release MA
228 0w40 Energy Release MA2
790 0w40 Motul MA2
892 0w40 Polaris MA2
1061 0w40 Max 4T MA
1334 0w40 4CT-40 MA

My RC45 has over 57K miles and those are miles not in moderation
either... its a homologated race bike with a first gear good for
90mph... since 98 I've been running 30 grade M1 EC oil 365
days a year... with no clutch slippage due to oil...
 
Last edited:
There is Dynamic Friction Characteristic Index (DFI), Static Friction Characteristic Index (SFI) and Stop Time Index (STI). SFI is done at low 300RPM speed, don't know about the other two, they may be done at high speed. That bullet specifically states in parenthesis "(high speed plate clutch)". Not sure why they would single that out.

Yes, it's friction and that's it. The test is done on a generic clutch, no accounting for different clutch materials, surface areas or engine output. That spec may be fine for applications that call for it, but not all. However it is recommended blindly for all applications, even ones that are 30-40 year old.
But recommend a non energy conserving oil, but without JASO and that is seen as a problem. Their standard clearly states that an oil must also meet the API, ILSAC or ACEA "other than Energy Conserving". So while JASO eliminates some of the guess work, it adds nothing on its own that would be specific to motorcycles, like say clutch material deposit control, tighter shear control or high temp. thinning. Nope, nothing of that sort.

1669777430275.png
Since none of us here have the detailed SAE friction test procedure, there may me details that would answer some of the unknowns about the friction testing. But since JASO T903 calls out 3 different kinds of standard friction tests and the specs, I'd bet that the SAE friction test can be setup to do all 3 tests to measure the friction specs laid out in the JASO documentation. Maybe there is a standard configuration on the SAE friction test machine, and that's what JASO has used for a baseline to define the friction targets (?). Need more details, but the fact is that hundreds of oils have been registered with JASO by submitting all the required specs and data.

So, people can trust JASO and use JASO rated oils, or they can put whatever they want in their cycles and do their own "testing". But wait, per BLS people don't have enough senses to realize the clutch might be slipping, but if they can it will be enough to really notice, and by then it's too late because that kind of clutch slippage will cause enough glazing to really make the clutch go south real fast. By the time someone notices major clutch slippage, it's already too late.
 
Motorcycle oil means higher cost and specific marketing... but both oils are remarkable the same... either the 0w40 or 10w40 will meet and exceed your mileage expectations...

Here are virgin oil samples of $4.89 a quart Mobil 1 Auto Oil 10W40
and $9.98 a quart Mobil 4T Motorcycle specific oil... the additive packages
are so similar that our wet clutch wouldn't know the difference...

full-45634-40107-mobil10w40v4t10w40.jpg



(warning additive package may not be current, check with the manufacture)

Really, again???
 
Last edited:
Motorcycle oil means higher cost and specific marketing... but both oils are remarkable the same... either the 0w40 or 10w40 will meet and exceed your mileage expectations...

Here are virgin oil samples of $4.89 a quart Mobil 1 Auto Oil 10W40
and $9.98 a quart Mobil 4T Motorcycle specific oil... the additive packages
are so similar that our wet clutch wouldn't know the difference...

full-45634-40107-mobil10w40v4t10w40.jpg



(warning additive package may not be current, check with the manufacture)


To those that may read the above post... BLS, this is irrelevant and misleading with the fact you have to put the caveat "additive packages may not be current".

You know very well the additive package for 10W-40 4T is not current, and this ancient analysis should never be used in good faith when professing "additive packages are so similar our wet clutches would never know the difference". You are either naïve and think everyone drinks Kool-Aid to the extent you do or, mercy sakes, wants to hear inaccurate regurgitation. This deliberate misrepresentation, over and over.
 
Ladies and Gentlemen, lend me your ears................... please call or ask your local dealer about whatever you are driving or riding what oils to run in your crankcase or gearbox....................... mercy sakes guys, its not rocket science and if it was rocket science most of us would not understand it since most folks in America run as fast as they can from High School and college courses in science and engineering, and I ran from English and punt-u ation as you cannot, like me, know where all the darn commas go,,,Im king of comma splicing...lol.....enjoy your day guys....ps, always buy your oil in the red color plastic bottles....lol
 
Ladies and Gentlemen, lend me your ears................... please call or ask your local dealer about whatever you are driving or riding what oils to run in your crankcase or gearbox....................... mercy sakes guys, its not rocket science and if it was rocket science most of us would not understand it since most folks in America run as fast as they can from High School and college courses in science and engineering, and I ran from English and punt-u ation as you cannot, like me, know where all the darn commas go,,,Im king of comma splicing...lol.....enjoy your day guys....ps, always buy your oil in the red color plastic bottles....lol
Dealer will recommend what is currently on their shelves, probably the branded product of their marque (HD, Honda, Kawasaki, Suzuki, Yamaha, etc.)

Also, BITOG will cease to exist if we heed your advice...

But you're still riding at 76, I gotta respect that!
 
Additive package read, doesnt tell you anything about the base oil, most CAR oils are Jaso MB (especially starburst energy efficient), defintely not clutch friendly, or at least the best clutch friendly oils.

And most of them will put out similar add packages.
 
Back
Top