Rotella 15w40 T4 & T6 in Motorcycles

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I agree that Shell knows oil... My personal experience is that T4 15w40 is a superior performing motor oil in my Honda motorcycles even compared to Honda brand dino oil. I haven't tried Honda's synthetic oil yet, probably never will.

My main curiosity with this thread is whether the T6 15w40 will outperform the same grade T4 15w40 in terms of resistance to sheer, high temps, extended OCIs, and cold starts.

I haven't had a problem with the T4 15w40 for cold starts as low as 32F, but I imagine the fully synthetic might just be a little smoother for cold starts, and give me a little more cushion on the OCI too.

I will likely still change the oil once a year, I'm lazy, but I like having a little extra cushion if I can get it.T5 did hold shift quality and stayed in grade. In my bike those things are pretty much synonymous. If it goes out of grade shift quality falls off if it is a x40 to start with. 20w50 conventional or synthetic has not fallen off in shift quality however Castrol 20 W 50 conventional
T5 15w40 did hold shift quality for 3700 miles for me. With that said T6 15w40 versus T4 in15w40 should hold shift quality longer, and by the numbers, shear less with respect to T6 being synthetic all else equal.

Conventional oil doesn't hold up as well for my bike and that should be pretty applicable to most shared sump bikes. Castrol 20w50 conventional was in the 40 wt range after 2700 miles, but shift quality was still good from what I remember. Valvoline 10w40 ATV oil was into the 30w range in just 1400 miles, and shifting had fallen off noticeably.

M1 20w50 and 10w40 4T are good for 5000+ miles in my bike and stay in grade. So, those are my go-to oils.
 

Jay Freddy

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Does anyone know the TBN for the T6 15w40?

I found Shell published documents that state 10.1 for the T4 15w40, and 10.6 for the T6 5w40.

Is there a database or repository with this information here on BITOG or elsewhere on the Internet?

Thanks!

ps. ...and Merry Christmas!
 
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I couldn't get Shell's product recommender to recommend T6 15W40 to me for a couple applications, so no, I don't know where they keep that doc. The T5 15W40 shows a TBN of 8.5 on the PDS from 12/17/21.
 
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I have never heard anyone claim that an oil that turns black faster is doing a better job! If that were a valid metric to gauge oil quality, a bunch of manufacturers would be selling black oil right out of the bottle... And wouldn't that have at least some correlation with the filter?!

Also, if T5 were good in wet clutch applications, why would Shell go through the trouble of getting T4 and T6 spec'd for JASO MA, but not T5?

Interesting thoughts! Thank you for your reply!
I’m trying to understand why a diesel oil even tested for JASO? And are there other diesel oils that have?? I didn’t know T6 was a full synthetic so am considering trying it in my bikes.
 
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I’m trying to understand why a diesel oil even tested for JASO? And are there other diesel oils that have?? I didn’t know T6 was a full synthetic so am considering trying it in my bikes.
My guess is because Shell knows that LOTS of motorcyclists use Rotella T, and they probably had the idea based on other testing that the fluid(s) are within or at least kinda reasonably close to the frictional requirements of MA.

We don’t actually know whether Shell even put any of the Rotellas through the friction tests, do we? No Rotella T is JASO certified (none on the actual certified oil list), and none that come to mind meet the spec for MB, MA, MA1, nor MA2 because they’re not API SL (or newer) certified, which is a requirement of JASO Mx certification.

Still, if the fluids meet the Mx frictional requirements, and motorcyclists have been happy with the fluid(s) overall, then so what?
 
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If your bike calls for 10w30..... It will love T6, 5w40..... Cause it will shear to a 30wt in a shared sump rather quickly.


...........

You're daft if you think your engine is going to love loosing power... running high temps... laboring harder against extra oil drag... it's tantamount to bike abuse calling for the slow moving 40 when your bike is lusting for the quick moving 30 grade... Oh the humanity!!!

Oil Drag is real...
full-45634-35309-oiltubeviscositytest.jpg
 
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I’m trying to understand why a diesel oil even tested for JASO?
JASO not much help... Shell Rotella can buy a Jaso cert for $365 no testing required...

As of 2021 Jaso has approved 469 10w30 and 33 5w30 and 20 0w30 oils...

JALOS does not test oils. They register oils based on manufacturer
data and site. Most of the data is generated by additive package
manufacturers. The system is just for registration. They hate any term
that implies their approval such as “certified by”.

Cost to register one grade of oil from one manufacturing site is
40,000 Japanese Yen or about USD $365.00.

JASO sets the standard. JALOS has the responsibility for the review
and registration. Once this is done you have the right to use the mark
on your labels. The documents submitted for review include the
technical performance data and label design.

Quote JASO
"The Panel may disclose the results of market surveys in a manner such
that particular names of submitters and their oil products are not
identifiable."

So no oil is currently listed to be the cause of wet clutch slip... fact is
high mileage not our oil is the observed cause of a clutch loosing its grip...
 

ZeeOSix

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JALOS does not test oils. They register oils based on manufacturer
data and site. Most of the data is generated by additive package
manufacturers. The system is just for registration. They hate any term
that implies their approval such as “certified by”.

Cost to register one grade of oil from one manufacturing site is
40,000 Japanese Yen or about USD $365.00.

JASO sets the standard. JALOS has the responsibility for the review
and registration. Once this is done you have the right to use the mark
on your labels. The documents submitted for review include the
technical performance data and label design.
I highly doubt any big name oil manufacture is going to make up test data to meet the JASO test specs, and then falsely submit it just to get it registered with JASO.

Quote JASO
"The Panel may disclose the results of market surveys in a manner such
that particular names of submitters and their oil products are not
identifiable."

So no oil is currently listed to be the cause of wet clutch slip... fact is
high mileage not our oil is the observed cause of a clutch loosing its grip...
Listed where? Are you saying someone has a list of oils that can cause wet clutch slip?
 
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You're daft if you think your engine is going to love loosing power... running high temps... laboring harder against extra oil drag... it's tantamount to bike abuse calling for the slow moving 40 when your bike is lusting for the quick moving 30 grade... Oh the humanity!!!


Yeah.... and most Motorcycle 30 weights are at the extreme high end of 30wt, darn near a 40 weight.

The microscopic power loss would only be a concern of someone that is daft.



..........
 
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Listed where? Are you saying someone has a list of oils that can cause wet clutch slip?

Jaso has approved 1,537 oils which covers just about everything in the
market... From 0w30 to 30 mono grades... from 0w30 to 20w60 multi grades...
from Auto to Cycle oils... What oil should a wet clutch customer stay way from???
JASO won't say... the results of market surveys are in a manner such
that particular names of submitters and their oil products are not
identifiable... I'm saying JASO needs to identify any oil that cause clutch slip...
 
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Yeah.... and most Motorcycle 30 weights are at the extreme high end of 30wt, darn near a 40 weight.

The microscopic power loss would only be a concern of someone that is daft.



..........
Oils are not graded on weight... oils are only graded on flow... what we know for sure is that a 30 flows quicker than 40... 1 to 2 HP loss is not microscopic not when customers spend $1,500 dollars for an exhaust or reflash a CPU with the hope of gaining 1 to 2 more HP... what is daft if you spend that much to gain 1 to 2 HP then switch from the prescribe 30 and run a 40 and loose 1 to 2 HP in unnecessary oil drag with zero gain in longevity...
full-45634-35394-viscositytest1.jpg
 

ZeeOSix

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Jaso has approved 1,537 oils which covers just about everything in the
market... From 0w30 to 30 mono grades... from 0w30 to 20w60 multi grades...
from Auto to Cycle oils... What oil should a wet clutch customer stay way from???
JASO won't say... the results of market surveys are in a manner such
that particular names of submitters and their oil products are not
identifiable... I'm saying JASO needs to identify any oil that cause clutch slip...
It doesn't cover many of the automotive motor oils on the market. The JASO list of MA//MA1/MA2 oils is far from "about everything on the market".
 
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ZeeOSix

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Oils are not graded on weight... oils are only graded on flow... what we know for sure is that a 30 flows quicker than 40...
Do you think 30 flows any faster through a pressurized oiling system than a 40 when a PD oil pump (not in pressure relief) is forcing the oil through the system? If so, explain how.
 

ZeeOSix

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Added what the actual most important characteristic of oil is.

1641159543737.jpeg
 
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