motorcycle and car oils

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Hello, I would like to get some light from you on this question: what is exactly the difference between car and motorcycle oils?
I've always heard a lot of talk on the matter, almost never supported by facts.
It's commonly being said that a bike engine runs at higher RPM, on hotter temperatures, and if you put in it a car oil you'll ruin the engine; beside that, people affirm that with car oil the tipical motorcycle's wet clutch will slip and the gearbox will become hard and noisy. But, on the other hand, there's a lot of people who says motor oils are all the same, just respect the recommended grade and API specs, an you'll be fine. After that, motorcycle oils cost about 2x or more than car oils, and this makes me become suspicious.

So, being these the JASO specs:

http://snipurl.com/282q7f5

and these the API ones:

http://snipurl.com/282q6rc


...is there anybody here that has the knowledge and experience to tell me the difference and shed some more light?

I'm no chemist or engineer, but it would seem to me that API rules are the most important thing, proven by the fact that Jaso itself requires the satisfaction of API rules; and that Jaso adds only something that regards strictly the clutch and transmission. Do you agree with that?
If this were true, there would be no risk at all by running a motorcycle engine on non-Jaso marked car oil; the only risk would be the possibility of having the clutch slipping in particular cases.

Am I right? What do you think about it?

Best,

DH
 
Plenty of people have run motorcycle engines in cars, myself included. One of the big motorcycle magazines did a comparison of several big motorcycle oils versus their car counterparts, and showed only slightly different additive levels. Motul 300V, for example, was the same except that the moto version had higher levels of boron.
 
Originally Posted By: dparm
Plenty of people have run motorcycle engines in cars, myself included. One of the big motorcycle magazines did a comparison of several big motorcycle oils versus their car counterparts, and showed only slightly different additive levels. Motul 300V, for example, was the same except that the moto version had higher levels of boron.


Motor cycle engines run in cars ?......very interesting !!
 
Originally Posted By: nitehawk55
Originally Posted By: dparm
Plenty of people have run motorcycle engines in cars, myself included. One of the big motorcycle magazines did a comparison of several big motorcycle oils versus their car counterparts, and showed only slightly different additive levels. Motul 300V, for example, was the same except that the moto version had higher levels of boron.


Motor cycle engines run in cars ?......very interesting !!



Doh, meant to say motorcycle oils.

But there are some project cars out there with motorcycle engines!
 
The oil companies found out it all about marketing. When I had my '82 Honda Goldwing, the manual said to use a good SAE motor oil.Nowadays, every motorcycle maker has their own brand of oil they recommend for their bikes. Do they make that oil? NO, it's contract is usually given to the cheapest bidder.Here's a fact most people don't realise, motorcycle specific oils don't have to pass any API test. If you look at any motorcycle specific bottle of oil, the only mention of API is they might SAY it meets some standard.Then again it doesn't have to. Because there is none. But if you check the VOA section, you can compare car oil and motorcycle oil VOA'S, and form your own opinion about which oil you want to use. The big differences are the additive paks. Diesel oils seem to have additive paks closer in line to motorcycle additive paks.Most oils seem to overdo it with the additives, and most get dumped at change time.I guess now that people can see that, alot are choosing that as a option to over priced motorcycle oils.Plus it seems your getting more bang for your buck with diesel oil.Cars oil bottles states the facts, Diesel truck oil might have a picture of a truck on it, nothing to get excited about, but just about every bottle of "motorcycle oil" has a picture of a motorcycle on it. So you can expect to pay upwards of $20 a qt for it. Like I said, it's all about marketing.,,
 
Originally Posted By: dharry
Hello, I would like to get some light from you on this question: what is exactly the difference between car and motorcycle oils?

Typically it's the add pack levels. The latest API certs have been successively reducing sulphated ash content to help extend the lives of modern emissions systems, and this ash content reduction is achieved by reducing additive levels. That is why many motorcycle owners manauals will say something like use API SH oil - this old API spec did not have the add packs limited as much as today's API SN for example.

However, it gets more complicated than this because the ZDDP limits only apply to Xw-20 and Xw-30 grades (or did I get this wrong?), so if you're going to be using Xw-40 or Xw-50 oil in your bike, then those limits may not even apply.

The other thing that you brought up was related to wet clutches. Many modern car oils have significant amounts of friction reducers to improve fuel economy. So say this is not the best for a wet clutch that does need some friction to operate correctly. But again, most Xw-40/Xw-50 oils aren't "energy conserving" to begin with, so do they really have too much friction reducers to harm a wet clutch?

I guess I'm saying it's a bit complicated, but it is possible to find a car engine oil that will work just fine in a motorcycle, so it is marketing driven to an extent. Take Mobil for example: their M1 15w-50 works great in wet clutches from what I've read; yet they don't market it as suitable for motorcycles because they can charge twice as much for their dedicated so called motorcycle oil.
 
Originally Posted By: aquariuscsm
I always used GTX 20W50 in my Honda CR500.


I trust you mean in the transmission, right? The CR was, after all, a two-stroke.....
 
Originally Posted By: Mik
Originally Posted By: aquariuscsm
I always used GTX 20W50 in my Honda CR500.


I trust you mean in the transmission, right? The CR was, after all, a two-stroke.....


howl!!!!
 
Yeah, I was gonna ask if he meant 'XR'...!

John.

Who always thought a CR500 was about the hairiest thing on two wheels. And the KX500 & the YZ490, etc....

Originally Posted By: sunruh
Originally Posted By: Mik
Originally Posted By: aquariuscsm
I always used GTX 20W50 in my Honda CR500.


I trust you mean in the transmission, right? The CR was, after all, a two-stroke.....


howl!!!!
 
the cr500 and kx500 were.....untill the yz450f (yz400f started it all), crf450r, kxf450, rmz450, sx450 came out. rev higher, more torque, more hp, same weight or lighter.
 
Originally Posted By: Quattro Pete
I guess I'm saying it's a bit complicated, but it is possible to find a car engine oil that will work just fine in a motorcycle


I asked that here, because I've been always using car oil, done TONS of kms on three different bikes, and never had any engine/gearbox/wet clutch issue... but when I tell this to the other bikers here in Italy they tell me I must be mad, that oil must strictly be JASO MA, and if it's not my engine will seize, clutch will slip and so on.
My method to choose oil is: get to next shopping mall, pick the cheaper 100% synthetic car oil of the bike's manual recommended grade (just check label for "energy conserving" additives), get home and do the job. Do you think I'm being safe enough?

thanks,

DH
 
I've used some 'car' oil in a previous motorcycle...for the autumn/winter 2012 oil change in my 2009 Yamaha V Star 650 Classic I used AutoZone (WPP product) 10w-40 pcmo for a bit over 500 miles without any problems; I've used some 'diesel' oil in my current motorcycle...shortly after getting my 2006 Honda Shadow Aero 750 I used Super Tech (WPP product) 15w-40 universal/diesel oil for nearly 700 miles (as a 'flush/cleaning' oil change) without any problems; even though I have enough Suzuki 'V Twin' synthetic blend (SOPUS product) 10w-40 motorcycle oil on hand for 2 oil changes in the motorcycle I am leaning toward using Shell Rotella-T 15w-40 next year to see how well it holds up during prime riding season in warmer temps;

one of my favorite shops, BMA Cycles in Bainbridge, PA, uses Castrol GTX in 10w-40 & 20w-50 for oil changes in motorcycles (unless the customer asks for Maxima 10w-40 or Amsoil 10w-40 or Amsoil 20w-50 that they also stock)...they have yet to experience any engine failures or clutch issues attributable to the Castrol pcmo they use
 
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I have been using Delvac MX 15w-40 in my Sportster transmission. Just got back from a Tour 2 up...no clutch slipping or wierd engagement either.
Cheers
 
Originally Posted By: Silverado12
FWIW I use Rotella 15W-40 in my H-D primary and no slippage at all. Works really well.


Ditto. I'm using it in the engine too.
 
Originally Posted By: sunruh
i drink it for breakfast.

right now im testing M1 0w40.


Check your PM. I'm very interested in the results.
 
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