Auto oil vs motorcycle
- Thread starter Tapman
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You make a general assumption that isn't totally true. Not all car oils are too "slippery", only those that use certain friction modifiers to achieve fuel economy benefits. These oils tend to be of a type that would not suit your engine, as they tend to be in the lower viscosity grades.
Weight and added size is a con. Don't over think it and let it bother you.
Harley does suggest you can run API diesel rated oil in the engine, but doesn't list any API / ILSAC / ACEA etc gasoline engine oil specs.
Many do run API gasoline engine spec oils in their bikes engine. No need to worry about friction modifiers in the engine, only the primary on the Big Twin bikes (primary/transmission on the Sportsters)
I have not seen any resource conserving (low friction) diesel rated oils in the viscosity ranges HD suggests.
If necessary and H-D 360 is not available, add oil certified for diesel engines.
Acceptable designations include: CH-4, CI-4 and CJ-4.
The preferred viscosity, in descending order are: 20W50, 15W40 and 10W40.
Many do run API gasoline engine spec oils in their bikes engine. No need to worry about friction modifiers in the engine, only the primary on the Big Twin bikes (primary/transmission on the Sportsters)
I have not seen any resource conserving (low friction) diesel rated oils in the viscosity ranges HD suggests.
If necessary and H-D 360 is not available, add oil certified for diesel engines.
Acceptable designations include: CH-4, CI-4 and CJ-4.
The preferred viscosity, in descending order are: 20W50, 15W40 and 10W40.
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Unless the bike has a shared sump wet clutch, you are likely okay using a gasoline automotive oil if the bike's engine block is water cooled. However, I'm not aware of any motorcycles that use water cooled engines without a shared sump wet clutch setup. Therefore, we're left with motorcycles featuring air cooled engine blocks with either air cooled heads, water cooled heads, or oil cooled heads. In the case of oil cooled heads we are talking some high temps the oil is exposed to, over and above that of typical gasoline car and truck engines. A heavy duty diesel oil must deal with cooling the piston crowns as typical diesel design has oil galleries under the crown. Therefore, diesel oils are built to be more thermally stable than gasoline engine oils and thus are often suitable for air cooled motorcycle engines, even with oil cooled heads.
My Moto Guzzi is an example of a "three hole" oiler, since it utilizes a reactive shaft drive, an automotive style dry clutch, and has separate lubrication circuits for engine, transmission, and final drive. The engine oil circuit includes oil cooled heads and a 2nd oil pump dedicated exclusively to moving oil through the heads and through a rather large oil cooler mounted high on the frame where water cooled bikes typically have the radiator. Gasoline automotive oil would not be suitable due to the oil cooled heads. Heavy Duty Engine Oil (diesel oil) of the proper viscosity would work, if one could be found in a 10W60 which is the viscosity the powertrain engineers who designed the engine say to use. Since that is not a common viscosity for HDEO, I use a JASO MA/MA2 compliant motorcycle specific synthetic 10W60 oil as recommended in the owner manual.
My Moto Guzzi is an example of a "three hole" oiler, since it utilizes a reactive shaft drive, an automotive style dry clutch, and has separate lubrication circuits for engine, transmission, and final drive. The engine oil circuit includes oil cooled heads and a 2nd oil pump dedicated exclusively to moving oil through the heads and through a rather large oil cooler mounted high on the frame where water cooled bikes typically have the radiator. Gasoline automotive oil would not be suitable due to the oil cooled heads. Heavy Duty Engine Oil (diesel oil) of the proper viscosity would work, if one could be found in a 10W60 which is the viscosity the powertrain engineers who designed the engine say to use. Since that is not a common viscosity for HDEO, I use a JASO MA/MA2 compliant motorcycle specific synthetic 10W60 oil as recommended in the owner manual.
Originally Posted by shanneba
Harley does suggest you can run API diesel rated oil in the engine, but doesn't list any API / ILSAC / ACEA etc gasoline engine oil specs.
Many do run API gasoline engine spec oils in their bikes engine. No need to worry about friction modifiers in the engine, only the primary on the Big Twin bikes (primary/transmission on the Sportsters)
I have not seen any resource conserving (low friction) diesel rated oils in the viscosity ranges HD suggests.
If necessary and H-D 360 is not available, add oil certified for diesel engines.
Acceptable designations include: CH-4, CI-4 and CJ-4.
The preferred viscosity, in descending order are: 20W50, 15W40 and 10W40.
^^ That^^
and for shared sump bikes you would be safe with most 20/50 and 10/40 oils. Or best choice, follow your owners manual.
To Loneranger -
The Harley Branded Oil is composed like a HDEO and why HD recommends HDEO "C" rated if HD not available however your explanation of why is not complete.
All late model HD touring bikes of the last decade or more require an HDEO "C" rated. Its not because of "oil cooled" valves as that only came out in the last couple years with the M8 engine.
Harley engines spray oil on the bottom of the pistons in order to cool them at highway speeds, we can only assume HD is concerned with piston and ring cleanliness (least amount of piston deposits) much like a diesel engine.
Any shared sump bike can use these HDEO/Diesel oils as they rarely contain any significant amount of moly for the simple reason that moly is a culprit when it comes to piston ring deposits.
Harley does suggest you can run API diesel rated oil in the engine, but doesn't list any API / ILSAC / ACEA etc gasoline engine oil specs.
Many do run API gasoline engine spec oils in their bikes engine. No need to worry about friction modifiers in the engine, only the primary on the Big Twin bikes (primary/transmission on the Sportsters)
I have not seen any resource conserving (low friction) diesel rated oils in the viscosity ranges HD suggests.
If necessary and H-D 360 is not available, add oil certified for diesel engines.
Acceptable designations include: CH-4, CI-4 and CJ-4.
The preferred viscosity, in descending order are: 20W50, 15W40 and 10W40.
^^ That^^
and for shared sump bikes you would be safe with most 20/50 and 10/40 oils. Or best choice, follow your owners manual.
To Loneranger -
The Harley Branded Oil is composed like a HDEO and why HD recommends HDEO "C" rated if HD not available however your explanation of why is not complete.
All late model HD touring bikes of the last decade or more require an HDEO "C" rated. Its not because of "oil cooled" valves as that only came out in the last couple years with the M8 engine.
Harley engines spray oil on the bottom of the pistons in order to cool them at highway speeds, we can only assume HD is concerned with piston and ring cleanliness (least amount of piston deposits) much like a diesel engine.
Any shared sump bike can use these HDEO/Diesel oils as they rarely contain any significant amount of moly for the simple reason that moly is a culprit when it comes to piston ring deposits.
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Moto Guzzi and I think BMW also use oil jetting at bottom of piston travel.
Originally Posted by Tapman
Logic tells me less friction in my engine the better.
Friction and wear are not the same thing.
Logic tells me less friction in my engine the better.
Friction and wear are not the same thing.
Originally Posted by Garak
Originally Posted by Tapman
Logic tells me less friction in my engine the better.
Friction and wear are not the same thing.
Being fair to Tapman, he never said or even implied that it was. He's got a point - less friction, in a system where friction leads to energy losses, can only be a good thing. Less wear is also a good thing, but not necessarily correlated to friction.
Originally Posted by Tapman
Logic tells me less friction in my engine the better.
Friction and wear are not the same thing.
Being fair to Tapman, he never said or even implied that it was. He's got a point - less friction, in a system where friction leads to energy losses, can only be a good thing. Less wear is also a good thing, but not necessarily correlated to friction.
I've never used Motorcycle oil. I just use 10w-40 and up. None of them are resourse/energy conserving.
You're absolutely right, weasley. I just jumped the gun on pre-empting the transposition of wear and friction. CAFE hasn't gotten to bikes yet, I don't think, so SHHHH!
There are biked that not shared sump and water cooled. KTM and Honda have both pulled this off.
been running scooters & metric bikes w/ common sumps for the past 8 years...used multiple brands of 10w-40 & 20w-50 pcmo's & 15w-40 hdeo's with great results; my bike trannies didn't like 20w-50's in cooler temps (bad shifting) so I tend to stick with XXw-40 oils; my favorite shop uses 10w-40 pcmo in new scooters (break-in) & bikes where owners want to use conventional oil for oil changes; I've also used limited quantities of 10w-30 hdeo's & supertech lawnmower oil to thin out oils for cold weather riding & storage...stuck with 10w-40 this year's storage
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I've also got 30+ years of using 'car' oils in my bikes. Everything from non-unit construction guzzi and bmws to late model sports and big air cooled unit construction 4's. Mileage from new to over 160,000 kilometres.
The wet clutch / car oil 'bogey man' is marketing hype trying to suck people into paying double digit $$ figures per litre for motorcycle specific oils. Total bulldust.
As long as the high quality (use a reputable brand) oil isn't classified as 'energy conserving' it'll be fine for bike use.
I've been using a local (Australian) blend by Penrite in 10w40 ( marketed as full syn but is really a group 3 with enough synthetic additives to legally be labelled as 'full synthetic ') for years in my cars, bikes, dirt bikes, kids mini bikes and quads. No issues with wet clutches even with extremely hard use.
My advice for what it's worth, save your money and put it toward more frequent changes.....not expensive advertising campaigns for bike oil companies.
btw BMW made liquid cooled, dry clutch (pre-unit construction) motorcycles.
Cheers Rick.
The wet clutch / car oil 'bogey man' is marketing hype trying to suck people into paying double digit $$ figures per litre for motorcycle specific oils. Total bulldust.
As long as the high quality (use a reputable brand) oil isn't classified as 'energy conserving' it'll be fine for bike use.
I've been using a local (Australian) blend by Penrite in 10w40 ( marketed as full syn but is really a group 3 with enough synthetic additives to legally be labelled as 'full synthetic ') for years in my cars, bikes, dirt bikes, kids mini bikes and quads. No issues with wet clutches even with extremely hard use.
My advice for what it's worth, save your money and put it toward more frequent changes.....not expensive advertising campaigns for bike oil companies.
btw BMW made liquid cooled, dry clutch (pre-unit construction) motorcycles.
Cheers Rick.
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I have a Harley road king that I use vr1 20w50 synthetic in that I got at autozone for 1.86 a qt, the primary gets rotella 15w40, the trans gets motorcraft 75w140 synthetic gear oil.
60k miles and zero problems, I boroscoped the cylinders and the crosshatch looks new.
60k miles and zero problems, I boroscoped the cylinders and the crosshatch looks new.
If it's a non-friction modified oil, it is fine. Doesn't need to be explained anymore than that. Talking liquid cooled motorcycle engines vs car engines, are you sure a car runs cooler? Where is that information found?
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