2016 CBR600RR - 10w40 ?

[ZeeOSix]

If an engine oiling system has a moderate pressure relief setting and you are operating beyond the relief set point - then it is no longer operating at constant volume (at x rpm and temp) but a constant pressure feed. Flow will indeed be greater with a lower viscosity lubricant under these conditions.

True, but when spring loaded bypass valved PD oil pumps are in relief, they typically still put out some increased flow with increased RPM, so they are not really perfect constant pressure devices unless it's some accurately computer controlled oil pump with closed-loop pressure feedback.

And even if they are in relief, the volume of oil supplied to the oiling system should still be adequate and above the required minimum level for proper lubrication if the system was designed correctly. When the supply volume is adequate, then the oil formulation and viscosity (HTHS and resulting MOFT) between the moving parts is what really matters.

 

[ZeeOSix]

Manual calls for 10w30

Is that the only viscosity called out, or is there a chart that shows other options like shown in post 14?

 

[Bonz]

I did some checking and looked like it was 10w30 only called out. Maybe someone can correct me on that?

 

[George7941]

I use Mobil Delvac 1300 10W30 in my CBR300R

 

[bioilcurious]

Who's the hotline to Honda that shared with you "Honda specifies 30 grade over 40 grade grade because it will..." for those reasons you attribute to Honda? Surely you wouldn't say that unless they said that specifically with respect to their bikes. Maybe it's in the owners manual, those key factors that were quoted?

Do you have a picture with them, interested to see who you have been talking with lately.

Hey @Bonz , I know you were poking fun @BusyLittleShop here, but if you go to the actual Honda lubricants site, they do say some interesting things:
https://powersports.honda.com/pro-honda-oils
This is from the site:
"Does 10W-30 provide superior performance in hot weather conditions?"
Yes. We tested Pro Honda 10W-30 in multiple weather conditions. In hot weather, it provides higher torque, lower motor heat, greater component protection, easier flow on cold starts, and less mechanical resistance. These all lead to higher horsepower, performance, fuel efficiency, and lower evaporation rates.

"Why is 10W-30 recommended for the 2007 and later models?"
Pro Honda designed and tested GN4 10W-30 to meet the exact needs of our 2007 and later model powersports. Lower viscosity prevents mechanical wear and improves engine power.

Also, it would appear from reading this site that Idemitsu makes the Honda oils.

 

[ZeeOSix]

"Why is 10W-30 recommended for the 2007 and later models?"
Pro Honda designed and tested GN4 10W-30 to meet the exact needs of our 2007 and later model powersports. Lower viscosity prevents mechanical wear and improves engine power.

That statement goes against the physics of Tribology. Pro Honda must have some Unicorn tears additive if the lower viscosity prevents mechanical wear.

What's the Kinematic Viscosity at 100C (KV100) and HTHS viscosity of this oil?

 

[Rygrego]

Hi Friends,

Manual calls for 10w30
I have purchased accidentally Mobil 1 4T Racing 10w40

Is that ok to use ?

Thank you

No issues at all.

 

[Bonz]

Hey @Bonz , I know you were poking fun @BusyLittleShop here, but if you go to the actual Honda lubricants site, they do say some interesting things:
https://powersports.honda.com/pro-honda-oils
This is from the site:
"Does 10W-30 provide superior performance in hot weather conditions?"
Yes. We tested Pro Honda 10W-30 in multiple weather conditions. In hot weather, it provides higher torque, lower motor heat, greater component protection, easier flow on cold starts, and less mechanical resistance. These all lead to higher horsepower, performance, fuel efficiency, and lower evaporation rates.

"Why is 10W-30 recommended for the 2007 and later models?"
Pro Honda designed and tested GN4 10W-30 to meet the exact needs of our 2007 and later model powersports. Lower viscosity prevents mechanical wear and improves engine power.

Also, it would appear from reading this site that Idemitsu makes the Honda oils.

I appreciate the post. I do not agree 10w30 is the best choice "in hot weather"(!). Yes, I am consterning when it comes to BLS and Honda now as well with that information. I would bet heavy coin, Honda tolerances haven't changed since the 80's on liquid cooled engines. The tolerances can only go to a certain point, whether that be bearings or piston/cylinder. Motorcycles aren't used 99% of the time in temps around freezing, so a 10w30 makes sense when temps are on the cooler side. On a 100° day in stop and go traffic, a 30 grade on top is turning to something thinner, IMO. Oil pressure drops with thinner oil to begin with before heat even enters in, MOFT goes away, etc. That's what I understand, happy to see info for the counterpoint. Always want to get better at understanding these things.

On the flip side, has heavier oil (10w40/15w40/20w50 vs 10w30) been shown to produce more wear or less engine longevity than the lighter grade oil? For me the upside of higher oil pressure, better MOFT and viscosity retention at higher temps makes more mechanical sense.

 

[ZeeOSix]

I appreciate the post. I do not agree 10w30 is the best choice "in hot weather"(!). Yes, I am consterning when it comes to BLS and Honda now as well with that information. I would bet heavy coin, Honda tolerances haven't changed since the 80's on liquid cooled engines. The tolerances can only go to a certain point, whether that be bearings or piston/cylinder. Motorcycles aren't used 99% of the time in temps around freezing, so a 10w30 makes sense when temps are on the cooler side. On a 100° day in stop and go traffic, a 30 grade on top is turning to something thinner, IMO. Oil pressure drops with thinner oil to begin with before heat even enters in, MOFT goes away, etc. That's what I understand, happy to see info for the counterpoint. Always want to get better at understanding these things.

I bet Honda doesn't spec 10W-30 for their air cooled engines. With a water cooled engine with an added oil cooler a 10W-30 would be acceptable if the ambient temperature isn't too hot as you mention. And of course as every thick vs thin discussion concludes, a grade higher isn't going to hurt and will provide more engine protection headroom - ie, more MOFT means more parts separation and added protection from wear.

Check this out. This is out of the 2000 Hayabusa OM. They show 10W-30 can be used, but only up to 30C (86F) ambient temperature. The 2000 Busa is liquid cooled and also has a large separate oil to air oil cooler. I always ran 0W-40 in mine.

Check out the size of the oil cooler on the Busa.

 

[Bonz]

Honda has switched to 10w30 for the XR650L, an air cooled engine notoriously hard on oil from heat and small oil capacity (~2qts). Was 10w40 up until it wasn't.

 

[ZeeOSix]

Honda has switched to 10w30 for the XR650L, an air cooled engine notoriously hard on oil from heat and small oil capacity (~2qts). Was 10w40 up until it wasn't.

I had to look to see if it uses an oil cooler, and apparently not. Sounds like there is some enhancements done to make the air cooling as efficient as possible. Do they recommend 10W-30 for all ambient temperature ranges?

 

[Bonz]

I looked in the 2024 owners manual online. It's a 10w30 spec, did not have a chart with other ambient ranges. Honestly, that recommendation says Honda does not care how long the engines last, and are not looking out for the customer. And in this day and age customers are more ignorant and unaware of oil, and how it works than ever before.

Interesting Honda calls for JASO MA and excludes MA2 by not mentioning MA2. To my understanding, MA spec'd bikes can use MA2 but MA2 spec'd bikes cannot "play down" to MA, technically speaking. Looks like Honda is trying to sell oil with only an MA spec hoping folks don't know they can use MA/MA2 spec'd oils from many other oil companies.

Last pic is from a UOA May of 2025 on BITOG. The engine was still breaking in, but look at the flashpoint, and look at the viscosity. Honda 10w30 oil is a 20 grade after ~1,900 miles even with a very high flashpoint. It's one case sample, however, I think it speaks volumes to tribolgy vs an owners manual.

 

[Japanese]

That statement goes against the physics of Tribology. Pro Honda must have some Unicorn tears additive if the lower viscosity prevents mechanical wear.

What's the Kinematic Viscosity at 100C (KV100) and HTHS viscosity of this oil?

Honda XR650L max. rpm: 6000 (single cyl.), doesn't come with tachometer, rider most likely doesn't go over 5000 rpm
Suzuki Hayabusa max. rpm: ~10,000 (4 cyl.), redline 11,000 rpm, rider often goes over 9,000 rpm
What do we compare here - rpm, speed, temp., friction, oil flow, oil shearing?

I couldn't find HTHS for this oil, but here is info on its KV at 100°C:

10.21 cSt (page 4), 2016
https://gacc.nifc.gov/gbcc/dispatch/id-eic/admin/SDS PDFs/Honda GN4 10W-30_Honda Australia Motorcycle and Power Equipment_SDS_3.30.2016.pdf

10.12 cSt (page 6), 2014
https://www.eastwestenviro.com/sds/2014-08-13_SDS_Oil-Engine-4-Cycle_Honda-GN4.pdf

9.70 cSt (page 5), 2021
https://defender.com/assets/pdf/hon...hCmmSMJStFmFSmem5SlZkOqyhKoRW0kQU1rnBXR9p4cq4

 

[Bonz]

I would disagree the rider of a Hayabusa "often goes over 9,000 rpm" while the XR650L rider "most likely doesn't go over 5,000 rpm". Any rider "often going over 9,000 rpm" on a Hayabusa is going over 70 mph in first, 105 mph in second, 125 mph in third, etc. That is not even at redline of 11,000 rpm, only somewhere a bit above 9,000 rpm according to data.

My feeling is Hayabusa riders would say they rarely, not regularly, go over 6,000 RPM (much less 9,000 rpm) in regular riding, including acceleration through the gears unless they want to lose their license or loop the bike.

Point being in all of this, Honda recommending their own 10w30 that shears in 1,900 miles to a 20 grade seems way out of line for best engine protection.

Personally, oil shearing and dropping out of grade is the determining factor for me as to the oil doing it's best to protect.

Anything (which is everything) for which Honda recommends a 10W-30 oil, M1 10w40 4T or similar oil with a good track record of maintaining grade should be the substitute and the discussion is over.

As a shared above, in 1,900 miles the Honda 10w30 oil was a 20 grade, on a bike that Honda spec'd 10w40 in for decades with no mechanical changes in the more recent years when they changed the spec to 10w30.

 

[ZeeOSix]

Interesting Honda calls for JASO MA and excludes MA2 by not mentioning MA2. To my understanding, MA spec'd bikes can use MA2 but MA2 spec'd bikes cannot "play down" to MA, technically speaking. Looks like Honda is trying to sell oil with only an MA spec hoping folks don't know they can use MA/MA2 spec'd oils from many other oil companies.

The way I take the JASO spec is if the manufacture recommends "MA" then you could use both MA1 or MA2 because MA covers the entire range of the specs. MA1 and MA2 are covering the two sub-ranges of MA - see table below.

If the manufacturer specifically recommends just MA1 or MA2, then that specific JASO spec should be used. But from the motorcycle oils I've looked at, it will either be MA or MA2 ... I've never seen one these days speced as MA1. My 2016 Yamaha XSR900 just specs MA, and I've been using MA2 oils.

Last pic is from a UOA May of 2025 on BITOG. The engine was still breaking in, but look at the flashpoint, and look at the viscosity. Honda 10w30 oil is a 20 grade after ~1,900 miles even with a very high flashpoint. It's one case sample, however, I think it speaks volumes to tribolgy vs an owners manual.

View attachment 300504
View attachment 300505
View attachment 300506

Yeah, that's a lot of KV100 loss in only 1,900 miles. Hopefully the wise owners of these bikes ignore the Honda OM and go with a good 10W-40. Wear metal levels are really high for 1,900 miles, but if this is the 2nd OCI then could be still breaking in as Blackstone mentioned. Has this BITOG member posted any UOAs after this one?

 

[ZeeOSix]

Honda XR650L max. rpm: 6000 (single cyl.), doesn't come with tachometer, rider most likely doesn't go over 5000 rpm
Suzuki Hayabusa max. rpm: ~10,000 (4 cyl.), redline 11,000 rpm, rider often goes over 9,000 rpm
What do we compare here - rpm, speed, temp., friction, oil flow, oil shearing?

Protecting an engine from wear is mainly about keeping the MOFT greater than zero for parts in mixed and hydrodynamic lubrication - the more MOFT the better, and having adequate viscosity is the only way to do that. More MOFT gives more wear protection headroom from parts rubbing and wearing. Parts in boundary lubrication rely a lot on the AW/AF additives and the resulting tribofilm, and of course the materials they are made from.

The MOFT goes down when the oil temperature goes up, when the load on the parts is higher (mainly apples to the rod and crank journal bearings, and when there is more shear rate in the film thickness. So higher power, higher RPM engines will benefit from higher HTHS viscosity oil. I agree with @Bonz that Honda seems to be pushing the limit by going to 10W-30 when they could have simply stayed with a 0W-40, even on a lower power, lower revving engine like the air-cooled XR650L.

Since CAFE (at least in the USA) doesn't apply to motorcycles (yet), so don't know why Honda is going with lower viscosity except to maybe give the engine a hair more HP and they think that's going to sell motorcycles. Japan also has regulations similar to a CAFE type requirement on motorcycles, so they just spec the thinner oil for every country the bike is sold in.

I couldn't find HTHS for this oil, but here is info on its KV at 100°C:

10.21 cSt (page 4), 2016
https://gacc.nifc.gov/gbcc/dispatch/id-eic/admin/SDS PDFs/Honda GN4 10W-30_Honda Australia Motorcycle and Power Equipment_SDS_3.30.2016.pdf

10.12 cSt (page 6), 2014
https://www.eastwestenviro.com/sds/2014-08-13_SDS_Oil-Engine-4-Cycle_Honda-GN4.pdf

9.70 cSt (page 5), 2021
https://defender.com/assets/pdf/hon...hCmmSMJStFmFSmem5SlZkOqyhKoRW0kQU1rnBXR9p4cq4

This is interesting, because as time went on from 2016 to 2021 the KV100 has been decreasing. KV100 of 9.3 is defined as the bottom of the 30 grade range, so 9.70 KV100 is a relatively thin 30 grade when new. No wonder it's getting into a 20 grade with some use.

 

[burbguy82]

Hi Friends,

Manual calls for 10w30
I have purchased accidentally Mobil 1 4T Racing 10w40

Is that ok to use ?

Thank you

My 2014 showed 10w40

 

[bioilcurious]

Since CAFE (at least in the USA) doesn't apply to motorcycles (yet), so don't know why Honda is going with lower viscosity except to maybe give the engine a hair more HP and they think that's going to sell motorcycles. Japan also has regulations similar to a CAFE type requirement on motorcycles, so they just spec the thinner oil for every country the bike is sold in.

You can read all about it on their global website for their pro honda oil.
https://global.honda/en/motorcycle-aftersales/prohonda/

"A commitment to low oil viscosity.
One of the great features of Honda engine oil is low viscosity.

In the past, many engine oils were unbalanced in terms of fuel economy and durability. These included single-grade oils and high-viscosity oils that increased friction loss, lowered engine performance and throttle response, and reduced fuel economy.

Honda also considers environmental impact and develops engine oil with a desire to protect the global environment.

To improve fuel efficiency and reduce CO2 while maintaining durability, Honda developed 10W-30 oil, which became the standard for Honda engine oil around the world.

Honda repeatedly conducts endurance tests at high temperatures, high loads, high revolutions and under conditions more severe than what customers encounter to ensure its low-viscosity engine oil delivers the best balance of fuel efficiency and durability.

We confidently recommend it to our customers."

"Uncompromising development
Honda’s engine oil development efforts focus on three points: fuel efficiency, durability and cost. However, satisfying all three is quite challenging.

Simply lowering oil viscosity, for example, improves fuel efficiency and lowers friction loss, but fails to meet durability

requirements. Using an expensive base oil to improve durability makes it impossible to meet the reasonable price requirement of Honda’s development concept.

Balancing fuel efficiency, durability and cost is extremely difficult, but we keep developing engine oil without compromise.

Our engine oils are rigorously tested on all Honda engines for a wide range of factors in usage environments around the world. So we are fully confident they meet our highest standards and can be used with assurance."

 

[ZeeOSix]

You can read all about it on their global website for their pro honda oil.
https://global.honda/en/motorcycle-aftersales/prohonda/

"A commitment to low oil viscosity.
One of the great features of Honda engine oil is low viscosity.

In the past, many engine oils were unbalanced in terms of fuel economy and durability. These included single-grade oils and high-viscosity oils that increased friction loss, lowered engine performance and throttle response, and reduced fuel economy.

Honda also considers environmental impact and develops engine oil with a desire to protect the global environment.

To improve fuel efficiency and reduce CO2 while maintaining durability, Honda developed 10W-30 oil, which became the standard for Honda engine oil around the world.

Honda repeatedly conducts endurance tests at high temperatures, high loads, high revolutions and under conditions more severe than what customers encounter to ensure its low-viscosity engine oil delivers the best balance of fuel efficiency and durability.

We confidently recommend it to our customers."

"Uncompromising development
Honda’s engine oil development efforts focus on three points: fuel efficiency, durability and cost. However, satisfying all three is quite challenging.

Simply lowering oil viscosity, for example, improves fuel efficiency and lowers friction loss, but fails to meet durability
requirements. Using an expensive base oil to improve durability makes it impossible to meet the reasonable price requirement of Honda’s development concept.

Balancing fuel efficiency, durability and cost is extremely difficult, but we keep developing engine oil without compromise.

Our engine oils are rigorously tested on all Honda engines for a wide range of factors in usage environments around the world. So we are fully confident they meet our highest standards and can be used with assurance."

Yeah, Honda has been researching and pushing lower viscosity oil for decades in their automotive line-up. The bold part basically says they have given up some wear protection for improved fuel economy. Even though they have claimed to have "rigorously tested for a wide range of factors in usage environments around the world", it doesn't mean that it's protecting the engine as well as a good 10W-40 grade oil. It just means the engines are performing a wearing at a level that Honda can accept.

 

[Bonz]

Honda has gone woke with respect to oil recommendation. It's ridiculous in a 10,000++ RPM shared sump engine to recommend a 10w30. It's shown if a rider values viscosity retention in the oil they purchase, 10w30 is not the way to go. IMO, it is irresponsible they recommend 10w30 knowing it will shear to a 20 grade. Someone will come along soon to say this is not accurate, however MOFT and separation of parts for longevity of an engine has been shown to be king.