Assuming your like me and don't ride if it's cold? Would a sae40 be better? Won't shear like a 10w40?
Is a straight weight better for a motorcycle
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I think multigrade oils are better for every engine. But, if the motorcycle is air cooled (no water cooled motors, they *need* multigrade) and the manufacturer recommended a single-weight oil when the motor was built, it won't harm anything.
I used single-weight 50 for quite a few years before switching to synthetic 20W-50, but that was because I had two 20-litre pails of AeroShell 100 (aviation 100 = SAE 50) to go through, that I got for free when the company I worked for converted the engines in the two DeHavilland Otter w/air cooled radial engines that they (still) own, to turboprops.*
You can't resell aviation oil, for the most part, unless it's in fresh, unopened containers (which these weren't), and the turbos don't use it, so a nice gift to me.
But my motor is 60 years old (built in Milwaukee in November 1957) and called for 50-grade when new. I think the bigger question would be can you run multigrade oil in an air-cooled four-stroke motorcycle, and I believe the answer is yes, and further if you can, you should.
Now that I look at my post, I should change my sig for the big twin oil.
* Powerplant: 1 × Pratt & Whitney R-1340-S1H1-G Wasp 9-cylinder air-cooled radial engine, 600 hp (448 kW)
Turbo conversion: 1 x Pratt & Whitney Canada PT6A-34, 750 shaft HP
I used single-weight 50 for quite a few years before switching to synthetic 20W-50, but that was because I had two 20-litre pails of AeroShell 100 (aviation 100 = SAE 50) to go through, that I got for free when the company I worked for converted the engines in the two DeHavilland Otter w/air cooled radial engines that they (still) own, to turboprops.*
You can't resell aviation oil, for the most part, unless it's in fresh, unopened containers (which these weren't), and the turbos don't use it, so a nice gift to me.
But my motor is 60 years old (built in Milwaukee in November 1957) and called for 50-grade when new. I think the bigger question would be can you run multigrade oil in an air-cooled four-stroke motorcycle, and I believe the answer is yes, and further if you can, you should.
Now that I look at my post, I should change my sig for the big twin oil.
* Powerplant: 1 × Pratt & Whitney R-1340-S1H1-G Wasp 9-cylinder air-cooled radial engine, 600 hp (448 kW)
Turbo conversion: 1 x Pratt & Whitney Canada PT6A-34, 750 shaft HP
I'm running SAE 30 in my old Stornello, works just fine...I'd never be out on it below 5C. BMW has 30 recommended from zero to 30 C, the temps I ride in, so will give it try after the next oil change.
Monogrades are 20w...25w anyway...
My bikes are water cooled. But use the oil for the engine and trans. I have seen 230f oil temps on my klr.
I'd say if you live in a warm climate and only ride when warm, it would be just fine. Especially in bikes that share the oil with the trans/engine because they really beat up oil.
Well let's see - bike ran on straight grades from 1903 to the 1980's and they did not have issues. Multi's will all shear down. Straight grades can not shear. There are no VII's.
As far as start-up wear, that's covered by residual film. A far as any pumped oil, as long as it's liquid, it will get there in the same time because it's a positive displacement pump.
There is no downside to straight grades, as long as it's not snowing outside ...
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As far as start-up wear, that's covered by residual film. A far as any pumped oil, as long as it's liquid, it will get there in the same time because it's a positive displacement pump.
There is no downside to straight grades, as long as it's not snowing outside ...
I've been running Valvoline VR1 SAE 40 in my bike (liquid cooled shared sump) for about a year now. Shift quality is amazing and doesn't degrade at all over the oil change interval. Which could be a problem if you're used to changing oil by shift feel - you may end up running the oil longer than you intended!
Even rode the bike over the winter with monograde in the sump. I should qualify this by saying that my bike is kept in a garage where the temperature doesn't drop below 50F so cold starts aren't difficult. At freezing and above, a monograde 40 is no thicker than a 20W-50.
I'd say give it a try, especially if your motorcycle's engine is particularly brutal on oil.
Edit addition:
You mentioned the 230F oil temp - if your intent is to try to lower it by changing the oil type, I'd opine that's not the best way to go. If anything, a monograde 40 will probably run a bit hotter (more viscous friction) than a multigrade 40. If your bike doesn't have an oil cooler, installing one would be the best way to bring the oil temp down.
Even rode the bike over the winter with monograde in the sump. I should qualify this by saying that my bike is kept in a garage where the temperature doesn't drop below 50F so cold starts aren't difficult. At freezing and above, a monograde 40 is no thicker than a 20W-50.
I'd say give it a try, especially if your motorcycle's engine is particularly brutal on oil.
Edit addition:
You mentioned the 230F oil temp - if your intent is to try to lower it by changing the oil type, I'd opine that's not the best way to go. If anything, a monograde 40 will probably run a bit hotter (more viscous friction) than a multigrade 40. If your bike doesn't have an oil cooler, installing one would be the best way to bring the oil temp down.
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Originally Posted By: Johnny2Bad
I think multigrade oils are better for every engine. But, if the motorcycle is air cooled (no water cooled motors, they *need* multigrade) and the manufacturer recommended a single-weight oil when the motor was built, it won't harm anything.
Why do liquid cooled engines need multigrade? And how would they know what kind of oil is inside them?
I think multigrade oils are better for every engine. But, if the motorcycle is air cooled (no water cooled motors, they *need* multigrade) and the manufacturer recommended a single-weight oil when the motor was built, it won't harm anything.
Why do liquid cooled engines need multigrade? And how would they know what kind of oil is inside them?
Originally Posted By: jeff78
You mentioned the 230F oil temp - if your intent is to try to lower it by changing the oil type, I'd opine that's not the best way to go. If anything, a monograde 40 will probably run a bit hotter (more viscous friction) than a multigrade 40. If your bike doesn't have an oil cooler, installing one would be the best way to bring the oil temp down.
naw. Just trying to find an oil that will shift smooth more than 50 miles.
You mentioned the 230F oil temp - if your intent is to try to lower it by changing the oil type, I'd opine that's not the best way to go. If anything, a monograde 40 will probably run a bit hotter (more viscous friction) than a multigrade 40. If your bike doesn't have an oil cooler, installing one would be the best way to bring the oil temp down.
naw. Just trying to find an oil that will shift smooth more than 50 miles.
Originally Posted By: Johnny2Bad
I think multigrade oils are better for every engine. But, if the motorcycle is air cooled (no water cooled motors, they *need* multigrade) and the manufacturer recommended a single-weight oil when the motor was built, it won't harm anything.
For bikes, if the multigrade achieved it without shearable polymers, then I'd agree.
If they have to get it by packing the oil with plastics, I disagree.
I think multigrade oils are better for every engine. But, if the motorcycle is air cooled (no water cooled motors, they *need* multigrade) and the manufacturer recommended a single-weight oil when the motor was built, it won't harm anything.
For bikes, if the multigrade achieved it without shearable polymers, then I'd agree.
If they have to get it by packing the oil with plastics, I disagree.
Originally Posted By: Chris142
Assuming your like me and don't ride if it's cold? Would a sae40 be better? Won't shear like a 10w40?
my testing proves it to be true
Assuming your like me and don't ride if it's cold? Would a sae40 be better? Won't shear like a 10w40?
my testing proves it to be true
I'm just going to say this as I always do in threads of this nature. Not all viscosity modifiers shear equally. There are some extremely shear stable polymers being used out there as well as some very unstable ones. It all depends on what the company is using as their polymer of choice.
Originally Posted By: jeff78
Originally Posted By: Chris142
naw. Just trying to find an oil that will shift smooth more than 50 miles.
Have you tried any of the 15W-40 diesel oils? They tend to be fairly tough.
Ya. Terrible!
Originally Posted By: Chris142
naw. Just trying to find an oil that will shift smooth more than 50 miles.
Have you tried any of the 15W-40 diesel oils? They tend to be fairly tough.
Ya. Terrible!
Originally Posted By: MotoTribologist
I'm just going to say this as I always do in threads of this nature. Not all viscosity modifiers shear equally. There are some extremely shear stable polymers being used out there as well as some very unstable ones. It all depends on what the company is using as their polymer of choice.
Are there any particular oil manufacturers that you would recommend as having higher quality, more shear stable viscosity modifiers than others?
I'm just going to say this as I always do in threads of this nature. Not all viscosity modifiers shear equally. There are some extremely shear stable polymers being used out there as well as some very unstable ones. It all depends on what the company is using as their polymer of choice.
Are there any particular oil manufacturers that you would recommend as having higher quality, more shear stable viscosity modifiers than others?
Originally Posted By: Analyzer
Originally Posted By: MotoTribologist
I'm just going to say this as I always do in threads of this nature. Not all viscosity modifiers shear equally. There are some extremely shear stable polymers being used out there as well as some very unstable ones. It all depends on what the company is using as their polymer of choice.
Are there any particular oil manufacturers that you would recommend as having higher quality, more shear stable viscosity modifiers than others?
Nope.
I would suggest asking a manufacturer what the shear stability results of their oils are according to JASO testing if you are interested in knowing.
Originally Posted By: MotoTribologist
I'm just going to say this as I always do in threads of this nature. Not all viscosity modifiers shear equally. There are some extremely shear stable polymers being used out there as well as some very unstable ones. It all depends on what the company is using as their polymer of choice.
Are there any particular oil manufacturers that you would recommend as having higher quality, more shear stable viscosity modifiers than others?
Nope.
I would suggest asking a manufacturer what the shear stability results of their oils are according to JASO testing if you are interested in knowing.
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