The Use of 5W Motorcycle Oils

[Quattro Pete]

Originally Posted By: Clevy
Really? Why exactly would they stamp the label with the JASO label if they didn't think it was able.

Yeah, I would have no problem using it in a shared sump/wet clutch, even though the T6 does tend to shear rather quickly when put in service.

But to clarify, neither T nor T6 actually carry a JASO logo on the label because they're not officially JASO certified. However, according to SOPUS, they meet the applicable JASO performance requirements.

 

[Cardenio327]

Originally Posted By: Analyzer
what is the recommended viscosity for your 400 in the Honda manual?


Owner's Manual:

API SG or better; JASO MA

0 to 40 °C 30
5 to 50 °C 40
0 to 50 °C 20w-50
0 to 45 °C 20w-40
-5 to 40 °C 10w-40
-10 to 30 °C 10w-30
-15 to 30 °C 5w-30
-30 to 20 °C 0w-30

Honda Service Manual (in Portuguese): Mobil Super 4T 20w-50

Service Bulletin: 10w-30 MA all temps.

Originally Posted By: Analyzer
Off topic, how's the weather down in Mexico? I'm in SoCal and was shocked with the cold snap we had these past 2 weeks, did you guys get similar or was it out of reach?


No cold weather here yet. High of 77 °F, low of 52 °F yesterday. Coldest it has gotten so far this fall is 45 °F. Last year is froze a few times and got down to 27 °F twice.

Back on topic: In non-competition use I don't see how viscosity could have a detrimental effect on the engine unless it sheared to below a 20 grade. I never gave much thought to the gears in the transmission as long as they don't grind until you mentioned it. Lots of automotive sticks use ATF which is about a 10w or so, so how much wear could a lower viscosity really cause?

 

[CentAmDL650]

Originally Posted By: Cardenio327
In non-competition use I don't see how viscosity could have a detrimental effect on the engine unless it sheared to below a 20 grade. I never gave much thought to the gears in the transmission as long as they don't grind until you mentioned it. Lots of automotive sticks use ATF which is about a 10w or so, so how much wear could a lower viscosity really cause?


Automotive manual transmissions use a different paradigm of power transmission from constant mesh transmission shared sump motorcycles. You have a series of mechanisms that move dogs to engage and disengage gears on various shafts in the transmission. The slides and the ratcheting mechanisms seem to work best when the oil is at or close to the spec viscosity grade.

As a rider who many years ago rode motocross and enduros, now riding 25 years later on a street bike, I am finding that point where the oil should be changed is fairly obvious when the shifting gets rougher and mis-shifts start happening. It's almost like a lightswitch when it happens, and it makes you more focused on synchronizing your throttle hand with the clutch movements and sometimes preloading the shift lever.

There are some oils that can make it shift super slick, and some that start out marginal and only get worse. And plenty with various degrees of the tactile sensation of lubrication through the boot, in the sounds of valvetrain, clutch, and bearings, and vibrationally through the saddle, the handlebars and footpegs. Makes you wonder how much the wear increases with oil in that condition.

And there are some bikes which are mix-masters of viscosity index improver doom, and others, esp. big street Hondas, which can seem to hold out for what would be an extended oil change interval even for a car. And so many farther from the extremes, but they all will eventually reach that problematic condition if their fill isn't OCI'd.

 

[CATERHAM]

Originally Posted By: Cujet
Originally Posted By: CATERHAM
Analyzer, from my Bike riding days, one easy way of determining if the oil you're using is getting to thin when the engine is hot, is a noticeable reduction is shift quality. Shifting become very notchy and if the oil gets very hot it can be very difficult to shift at all.
So if you can maintain good shift quality on a 0W/5W-30 oil you don't need to run anything heavier.


It's interesting how oil "talks" to us, isn't it? Not sure that's a 100% scientific method, but I believe it has validity. My SV1000s certainly likes frequent oil changes, and the shifting starts "going south" after about 1500 miles. Even with top shelf, full syn oils.

I'm sure if you installed an oil pressure gauge (yes they have them for bikes), you'd find that shift quality correlates closely with operational viscosity which OP is a proxy for. So regardless of the oil grade and brand you use, the combination of oil shear, OCI and max' oil temperatures will net a minimum operational viscosity that maintains acceptable shift quality. Since the gear cluster in a bike has a higher viscosity demand that what the engine requires, shift quality is what experienced riders rely upon to choose what oil and OCI combo'.

Clevy found a dino 15W-40 was the most cost effective oil choice for his bike and the way he rides. I found a straight 30 grade was very good for a Honda I had after trying a number of 30 and 40 multi-grades.

 

[Cujet]

Originally Posted By: CATERHAM

I'm sure if you installed an oil pressure gauge (yes they have them for bikes), you'd find that shift quality correlates closely with operational viscosity which OP is a proxy for. So regardless of the oil grade and brand you use, the combination of oil shear, OCI and max' oil temperatures will net a minimum operational viscosity that maintains acceptable shift quality. Since the gear cluster in a bike has a higher viscosity demand that what the engine requires, shift quality is what experienced riders rely upon to choose what oil and OCI combo'.


Ya know, that's a really good idea. I'd love to have an oil pressure gauge on my SV1000s, just to see how the oil is doing in general operation.

What you say, seems to make sense on the surface. However, I remain unconvinced that viscosity is the only factor involved in shift quality. I'm an experienced motorcyclist, and on my 47th motorcycle. Having ridden various bikes for many years, instead of owning a car.

My oil change history included plenty of viscous oils, including high end synthetics and conventional oils. I've not been able to make the connection between sheer, viscosity and shift quality yet. But, I could be dumb as a box of rocks.

 

[tc1446]

Originally Posted By: Cujet
T6 is a commonly used oil in motorcycles. Regardless of the manufacturers specifications. Most people give it high marks. And, I don't recall ever reading any sub standard results, other than the possibility of slightly more rapid shearing. Many of the "tour" guys do with with fantastic UOA results.

I'm convinced that shared sump motorcycle engines should have frequent oil changes for all the expected reasons. Shear, particulate count, iron, clutch material, etc. With that in mind, I'm not at all of the mindset that you need an oil that is 100% shear stable for 15,000 miles when the oil should come OUT at 2500 miles!


Cujet, your second para above hits the nail on head for me! In my quest for an oil that will hold up for 4000-4500 mi in my Can Am, partly due to difficulty of changing two filters each time, It never occurred to me to simply dump the oil at at 2 or 2.5K and then do the filters at the second oil change. Makes perfect sense. Sometimes the simplest solution is overlooked.

 

[Analyzer]

Originally Posted By: Cardenio327
Originally Posted By: Analyzer
what is the recommended viscosity for your 400 in the Honda manual?


Owner's Manual:

API SG or better; JASO MA

0 to 40 °C 30
5 to 50 °C 40
0 to 50 °C 20w-50
0 to 45 °C 20w-40
-5 to 40 °C 10w-40
-10 to 30 °C 10w-30
-15 to 30 °C 5w-30
-30 to 20 °C 0w-30

Honda Service Manual (in Portuguese): Mobil Super 4T 20w-50

Service Bulletin: 10w-30 MA all temps.

Originally Posted By: Analyzer
Off topic, how's the weather down in Mexico? I'm in SoCal and was shocked with the cold snap we had these past 2 weeks, did you guys get similar or was it out of reach?


No cold weather here yet. High of 77 °F, low of 52 °F yesterday. Coldest it has gotten so far this fall is 45 °F. Last year is froze a few times and got down to 27 °F twice.

Back on topic: In non-competition use I don't see how viscosity could have a detrimental effect on the engine unless it sheared to below a 20 grade. I never gave much thought to the gears in the transmission as long as they don't grind until you mentioned it. Lots of automotive sticks use ATF which is about a 10w or so, so how much wear could a lower viscosity really cause?


Thanks for the detailed manual info! Looks like the 5W is recommended down to -15C (5 degrees F), but the 10W30 service update for all temps is surprising, especially since the API specs the use of 10W down to zero degree startups.
http://www.api.org/certification-programs/engine-oil-diesel-exhaust-fluid/~/media/Files/Certification/Engine-Oil-Diesel/Publications/MOM_GUIDE_ENGLISH_2013.pdf

Man that is some awesome temps for winter! I'm on the central coast of CA (about 200 miles north of l.a) and we have gotten down to 17 degree F mornings! Needless to say the bike stayed garaged for those mornings lol.

Yeah there are some manual transmissions like the Synchromesh variety that run lower viscosity grades, but there's still a lot of manual transmissions that run heavier grades also; but this also depends heavily as CentAmDL650 said on the type of transmission. None the less, the automotive manuals you're talking about are simply lubricating the transmission (and thus in theory could operate with a thinner weight) where as the motorcycle has not only the gearbox, but clutch and engine to simultaneously contend with.

CATERHAM, It's not the operating viscosity that has me concerned, as the manufacturers generally recommend 30, 40, or 50 weights, but is the 5W providing enough protection until the oil viscosity has been increased due to oil temperature that has me concerned. I think that would be an awesome test to run with an oil pressure gauge as you suggested, nice idea! Transmission shifting feel can definitely be a useful tool in assessing the shear stability of the oil, but I don't think it can be relied upon exclusively.

rossn2- Rotella T6 has been approved for wet clutch compatibility since SOPUS states it meeta JASO MA standards, so you'd be safe to us it.

I think I might have come up with a crude analogy that might make a little more sense as to what I'm concerned about. For instance, if we take a look at the UOA's compiled for the same bike over similar use (I think Sunruh's would be a prime example) by randomly clicking on his posts I found varied wear of aluminum from as low as 7 PPM, all the way on up to 46 PPM. I think the vast majority of riders would not have been able to "tell/notice" a difference between the two oils even though they had vastly different wear rates, almost upwards of 7 times the wear, i.e, "Man, I think this oil is wearing my engine/gearbox at a faster rate than the previous oil I used".
I think shifting feel can be a helpful tool, but I think there could be potential wear that we could not feel or distinguish during the short period of time that we're shifting that over the course of thousands of miles, could lead to premature wear; hence the possible reason the motorcycle manufacturers I initially posted that sell their own oil (and also many that don't) don't recommend or make/supply their brand specific oil in anything lower than a 10W. Does that make sense? Crude analogy I know, but the best I could come up with on the spot.

 

[Shannow]

Originally Posted By: Cujet
Originally Posted By: CATERHAM

I'm sure if you installed an oil pressure gauge (yes they have them for bikes), you'd find that shift quality correlates closely with operational viscosity which OP is a proxy for. So regardless of the oil grade and brand you use, the combination of oil shear, OCI and max' oil temperatures will net a minimum operational viscosity that maintains acceptable shift quality. Since the gear cluster in a bike has a higher viscosity demand that what the engine requires, shift quality is what experienced riders rely upon to choose what oil and OCI combo'.


Ya know, that's a really good idea. I'd love to have an oil pressure gauge on my SV1000s, just to see how the oil is doing in general operation.

What you say, seems to make sense on the surface. However, I remain unconvinced that viscosity is the only factor involved in shift quality. I'm an experienced motorcyclist, and on my 47th motorcycle. Having ridden various bikes for many years, instead of owning a car.

My oil change history included plenty of viscous oils, including high end synthetics and conventional oils. I've not been able to make the connection between sheer, viscosity and shift quality yet. But, I could be dumb as a box of rocks.


Given that Oil Pressure is apparently indicative of HTHS, and not KV...and given that IIRC motorbike gears are dog engaged...not sure that with OP, anything is being measured that is remotely applicable to shift quality.

 

[Cardenio327]

Originally Posted By: CentAmDL650
Originally Posted By: Cardenio327
In non-competition use I don't see how viscosity could have a detrimental effect on the engine unless it sheared to below a 20 grade. I never gave much thought to the gears in the transmission as long as they don't grind until you mentioned it. Lots of automotive sticks use ATF which is about a 10w or so, so how much wear could a lower viscosity really cause?


Automotive manual transmissions use a different paradigm of power transmission from constant mesh transmission shared sump motorcycles. You have a series of mechanisms that move dogs to engage and disengage gears on various shafts in the transmission. The slides and the ratcheting mechanisms seem to work best when the oil is at or close to the spec viscosity grade.

As a rider who many years ago rode motocross and enduros, now riding 25 years later on a street bike, I am finding that point where the oil should be changed is fairly obvious when the shifting gets rougher and mis-shifts start happening. It's almost like a lightswitch when it happens, and it makes you more focused on synchronizing your throttle hand with the clutch movements and sometimes preloading the shift lever.

There are some oils that can make it shift super slick, and some that start out marginal and only get worse. And plenty with various degrees of the tactile sensation of lubrication through the boot, in the sounds of valvetrain, clutch, and bearings, and vibrationally through the saddle, the handlebars and footpegs. Makes you wonder how much the wear increases with oil in that condition.

And there are some bikes which are mix-masters of viscosity index improver doom, and others, esp. big street Hondas, which can seem to hold out for what would be an extended oil change interval even for a car. And so many farther from the extremes, but they all will eventually reach that problematic condition if their fill isn't OCI'd.


I guess I got lucky and got a bike that wasn't built on a Monday or a Wednesday or a Friday

The only oil that I've tried that caused unsatisfactory shifting was Honda Genuine HP4 10w-40, so unsatisfactory that I didn't leave it in long enough to give it a chance.

Typically it shifts beautifully the day of the oil change, gets a little rough within a day or two then gradually gets better reaching a plateau after a couple of weeks, and stays the same for the rest of the year. Just a little "snick" with every gear change up or down 95% of the time.

As I understand it the oil related rough shifting has nothing to do with the gears and whatnot, it is the oil between the clutch plates that causes the roughness.

Maybe shifting technique has something to do with it? I was taught by my dad to never lug an engine, and seldom do it. I upshift between 4,000 and 6,500 rpm in regular driving, at 8,000 WOT a few times a week to blow out the carbon. From stoplight to stoplight if I can get there without exceeding 6,000 or 7,000 I just leave it in 1st, no need to waste fuel or wear shifting. I match rpm after downshifts and downshift between 2,500 and 4,500 rpm. On coast downs to stop I de-clutch at 1,000 rpm, wait until 20 Km/h to downshift through the gears to 2nd, and downshift to 1st at 5 to 10 Km/h.

I always keep the clutch well adjusted as well. Manual calls for 5/8" freeplay, I prefer to keep it at 11/16". And, I always use the clutch, no powershifting.

 

[Silk]

Originally Posted By: Cardenio327
In non-competition use I don't see how viscosity could have a detrimental effect on the engine unless it sheared to below a 20 grade. I never gave much thought to the gears in the transmission as long as they don't grind until you mentioned it. Lots of automotive sticks use ATF which is about a 10w or so, so how much wear could a lower viscosity really cause?


ATF is very often used in 2 stroke motorcycle gearboxes, these are the same constant mesh wet clutch systems used in shared sump bikes. Manufacturers usually spec a 30 or these days a 10/30, but ATF works well. Sometimes I notice shift quality with oils, more often not. I've usually sold the bike before I settle on what works.

 

[Mackelroy]

works well as far as the clutch, but Ive heard metal content is pretty high, there's just no gear cushion at all with atf for a tranny.

 

[Mackelroy]

From what I ve gathered, the 5w30, 10w30, 5w40,10w40 ect. Stay much closer to the actual weights in both extremes of temps than straight weights which vary much greater.
take a 30 weight, its going to be like a 60 weight at freezing, and a 5 weight at full temp. That may be an exaggeration, but its the drift.

Another thread similar topic discussed, and a 5w30 was closer to a 25 weight at freezing, Course a straight 25 weight at freezing would be expected to act more like a 50 weight, maybe not exact but you get the drift.

in essance you can disregard the ow , or the 5 w , or the 10 w, and focus on the main weight for cold start, it wont be that far off.

 

[Clevy]

Originally Posted By: Mackelroy
From what I ve gathered, the 5w30, 10w30, 5w40,10w40 ect. Stay much closer to the actual weights in both extremes of temps than straight weights which vary much greater.
take a 30 weight, its going to be like a 60 weight at freezing, and a 5 weight at full temp. That may be an exaggeration, but its the drift.

Another thread similar topic discussed, and a 5w30 was closer to a 25 weight at freezing, Course a straight 25 weight at freezing would be expected to act more like a 50 weight, maybe not exact but you get the drift.

in essance you can disregard the ow , or the 5 w , or the 10 w, and focus on the main weight for cold start, it wont be that far off.



K. My head hurts......a lot.
Sir. I'm not going to write anything other than perhaps taking some time to read not only every article written on the home page but every single google hit when you search multi-grade engine oil and straight grade or SAE because this comment is so offside I'd delete it before anyone sees it.

 

[Quattro Pete]

Originally Posted By: Clevy
K. My head hurts......a lot.

Mine does, too. It's gotta be from the "drift."

 

[OVERKILL]

Originally Posted By: Mackelroy
From what I ve gathered, the 5w30, 10w30, 5w40,10w40 ect. Stay much closer to the actual weights in both extremes of temps than straight weights which vary much greater.
take a 30 weight, its going to be like a 60 weight at freezing, and a 5 weight at full temp. That may be an exaggeration, but its the drift.

Another thread similar topic discussed, and a 5w30 was closer to a 25 weight at freezing, Course a straight 25 weight at freezing would be expected to act more like a 50 weight, maybe not exact but you get the drift.

in essance you can disregard the ow , or the 5 w , or the 10 w, and focus on the main weight for cold start, it wont be that far off.


That was most definitely NOT what was established in the other thread sir.

 

[Mackelroy]

You mean that a 5w30 did not act like a 25 weight at freezing, thats what the cst's indicated to me, by your cst charting.

Which really stands to reason. Cause if comparing a straight 30 weight at freezing, it would be much thicker, way higher viscosity. The 5 winter keeps that from happening, and thats about it in a nutshell.

I dont see how thats way off base.

 

[OVERKILL]

Originally Posted By: Mackelroy
You mean that a 5w30 did not act like a 25 weight at freezing, thats what the cst's indicated to me, by your cst charting.

Which really stands to reason. Cause if comparing a straight 30 weight at freezing, it would be much thicker, way higher viscosity. The 5 winter keeps that from happening, and thats about it in a nutshell.

I dont see how thats way off base.


You are assigning weights to temperatures and that's not what we spoke of in the other thread. Your statement that I replied to here:

Quote:
From what I ve gathered, the 5w30, 10w30, 5w40,10w40 ect. Stay much closer to the actual weights in both extremes of temps than straight weights which vary much greater.
take a 30 weight, its going to be like a 60 weight at freezing, and a 5 weight at full temp. That may be an exaggeration, but its the drift.


Doesn't make sense because the "w" or "winter" designation is independent of the "hot" viscosity of the oil, which is measured at 100C. An SAE 30 behaves like an SAE 30 at 0C. And a 5w-30 behaves like a 5w-30 at 0C. The 5w-30 flows better because it has the 5w designation, meaning that it falls at or below the maximum CCS viscosity requirement of the 5w designation, which is measured at -30C.

What I think you are referencing is the discussion we had as to how the multi-weight designation corresponds with a given straight-weight at 0C and the charts I made using the Widman Viscosity Calculator:

Which shows that at 0C, a 5w-30 was significantly heavier than even an SAE 15 lubricant.

That said, the CCS values that determine the performance of a given multigrade oil aren't measured at 0C, they are measured as specific temperatures depending on their "W" or "Winter" designation. 0w-xx is measured at -35, 5w-xx at -30, 10w-xx at -25, 15w-xx at -20 and 20w-xx at -15. So while it may be (and it was) a fun exercise to see what straight-weight corresponds to a given multigrade at 0C, it wasn't really fruitful in determining anything useful other than that. Ergo, the initial statement you made in this thread is more confusing than anything, as it seems to extend that exercise beyond the scope it was designed to explore.

 

[Shannow]

When you've got people on the board claiming that a 20 when at 80C is really a 30, Redlines 20s are really 30s, and splitting gradings within API ranges to suit their argument...it's not surprising people get confused.

 

[Ducman]

Originally Posted By: Shannow
When you've got people on the board claiming that a 20 when at 80C is really a 30, Redlines 20s are really 30s, and splitting gradings within API ranges to suit their argument...it's not surprising people get confused.


Agreed

 

[eddy21]

I assume the manufacturer designed the oiling system, Bearing clearances etc for a certain weight oil. Why 2nd guess them? do they have an ulterior motive?