why do motorcycle oils never fall below 10W ?

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just wondering this. never seen a BRANDED motorcycle oil fall below 10W

any real reason for this?

because I see plenty of non motorcycle oils that are 0W and 5W that still pass the JASO MA spec. however it is a car oil (which is fine I know as long as JASO spec)

id like to get to the reason why they dont make a 5W or a 0W. as I live in 4 degree Celsius temps in the winter. and when I look at 15W and 10W in my sight glass it looks a little thick. I know 15W will crank to -20 (probably -5 safely) but it looks way too thick
 
Honda did spec a 5wxx many years ago for the CBR 900 Fireblade (SC28) in Germany and quickly revised their recommendation when the dealers were littered with blown engines. Shared sumps tends to shear the oil badly in a short time.
 
Harley recommends 10w 40 wt when th e temps are 40f or lower. Normally it's 20w50 wt. Up to straight 60wt when temps are over 80f. But like MOM said, not too many want to ride when it's 12 degrees.,,,
 
I actually wonder why the bulk of all motorcycle oil isn't single grade (SAE 40, for example) since most folks who ride in the US seem to do it for recreation rather than need. I would bet you guys in AUS would do just fine with a single grade oil as well given your temps?
 
I've seen several major brands with 0wXX and 5wXX oils. The 0w oils were usually branded as Racing oil, and were expected to be changed very frequently, and the engine disassembled, inspected, and overhauled often.
 
Originally Posted By: jack11234
just wondering this. never seen a BRANDED motorcycle oil fall below 10W

any real reason for this?

because I see plenty of non motorcycle oils that are 0W and 5W that still pass the JASO MA spec. however it is a car oil (which is fine I know as long as JASO spec)

id like to get to the reason why they dont make a 5W or a 0W. as I live in 4 degree Celsius temps in the winter. and when I look at 15W and 10W in my sight glass it looks a little thick. I know 15W will crank to -20 (probably -5 safely) but it looks way too thick


You're close, a typical 10WXX oil will have pumpability down to 0 degrees Fahrenheit (-18 degrees celsius), so you riding at 4 degrees ambient temp. is well within range.

Some BMW's like the K1600 spec a 5W40 viscosity oil, but most manufacturers recommend a 10WXX or higher. This was one of the primary reasons the JASO specification was created due to the automotive industry leaning toward thinner viscosity lubricants with increased friction modifiers. This lead to clutch slippage, and increased drive-line wear (primarily excessive gear wear/pitting). A 40 grade engine oil at operating temperature is equivalent to an SAE 90 gear oil, and when the 40 grade engine oil shears down to a 30 grade you're equivalent to an SAE 80/85 gear oil. This ensures adequate protection of the transmission where thinner viscosities may not have enough oil film thickness to minimize wear.

BITOGA Oil Viscosity Chart

Jaso Implementation Manual
 
you talk about shearing and oil viscosity. but I know enough about oil that the W just means the minimum ambient temp. how can a 0W 50 shear faster than a 15W 50 when it has the same operational viscosity ?

the oil I am looking has JASO MA spec and says safe for wet clutches at 5W 50 however not a motorcycle branded oil
 
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My 2013 Yamaha calls for 20W40. Thats a hard oil to find. I'm using 10W40 Valvoline motorcycle right now, with 15W40 Rotella on deck.

As to the ops question, a 10W40 is a lot less likely to sheer than a 5W40 is my guess. Plus hardly anyone rides when its 0 degrees C or colder.
 
Originally Posted By: motor_oil_madman
Maybe they figure most aren't going to ride a motorcycle when it's -15 degrees outside?


but it is a dry cold.
 
Perhaps your average biker thinks about their engine a bit more than does your average car driver?

And maybe there isn't a bikers CAFE?
 
Originally Posted By: jack11234
the oil I am looking has JASO MA spec and says safe for wet clutches at 5W 50 however not a motorcycle branded oil


A Penrite car oil by any chance? I use one of their 5w30 car oils (wet clutch safe) in my Honda 750, works fine.
 
5w40
http://www.maximausa.com/product/extra4/

EXTRA4 is a 100% synthetic triple ester engine oil featuring advanced additive technology. By using today’s most advanced additive systems and high-performance synthetic ester based stocks, we have engineered what we believe to be the finest 4-cycle motorcycle specific oil available on the market today. The very latest shear stable polymer systems have been used to assure viscosity stability and virtually eliminate transmission “shear-down” of the oil. Exceeds API SL and JASO MA specifications
 
Originally Posted By: jack11234
you talk about shearing and oil viscosity. but I know enough about oil that the W just means the minimum ambient temp. how can a 0W 50 shear faster than a 15W 50 when it has the same operational viscosity ?

the oil I am looking has JASO MA spec and says safe for wet clutches at 5W 50 however not a motorcycle branded oil



Because the operational viscosity is not achieved the same way. One uses more VII's to get the cold pumpabiliy. And these are more prone to shearing than base oil. The narrower the viscosity band, the less adulteration in the oil and the more stable (apples to apples, of course).
 
Originally Posted By: krismoriah72
5w40
http://www.maximausa.com/product/extra4/

EXTRA4 is a 100% synthetic triple ester engine oil featuring advanced additive technology. By using today’s most advanced additive systems and high-performance synthetic ester based stocks, we have engineered what we believe to be the finest 4-cycle motorcycle specific oil available on the market today. The very latest shear stable polymer systems have been used to assure viscosity stability and virtually eliminate transmission “shear-down” of the oil. Exceeds API SL and JASO MA specifications


FWIW, Motul also offers 300V in 5w40...
 
Originally Posted By: jack11234
you talk about shearing and oil viscosity. but I know enough about oil that the W just means the minimum ambient temp. how can a 0W 50 shear faster than a 15W 50 when it has the same operational viscosity ?

the oil I am looking has JASO MA spec and says safe for wet clutches at 5W 50 however not a motorcycle branded oil



In simple terms,
Both oils have "plastic" in them that expand when hot, this creates an oil with a viscosity of 50.
This "plastic" gets sheared down by the gear cases of many bikes and then no longer as effective.

So an oil labeled 5w will have more viscosity agent in it (Plastic that expands) to ACT like a 50 weight oil when hot. The more plastic, the more shearing.
A 15 or 20 W oil will already be closer to the 50 weight and will have less viscosity agents (plastic) to shear.

There isnt a magical oil that is all viscosity's in a multi viscosity oil the true viscosity is somewhere in-between the 5/50 numbers and 15 or 20/50 numbers.

The more spread in numbers, the more viscosity agents, the more shearing.

and lets not forget (I think someone mentioned it in the posts above) the less adulteration to the oil, the more actual oil which is the best anti wear agent to begin with!
 
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Originally Posted By: simple_gifts
Originally Posted By: motor_oil_madman
Maybe they figure most aren't going to ride a motorcycle when it's -15 degrees outside?


but it is a dry cold.


laugh.gif
 
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