Motorex 10w/60?


4 replies to this topic
  • inte

Posted January 11, 2005 - 04:38 PM

#1

I've got it for my KTM 640 Adventure & everyone says it's great stuff ... just real expensive.

Any reason not to use it in my YZ426? The YZ manual recommends 10/30, 10/40, or 10/50 (in the Yamalube) - I assume the 10/60 would just allow the oil to work in slightly hotter temps. Yes?

  • grayracer513

Posted January 11, 2005 - 05:19 PM

#2

I would not use this oil on 3 counts, mainly 2. One is that it's heavier than I need to have. A 10w-40, or 20w-40 is good for everything up to 114 degrees F. A ?w-50 is OK to somewhere beyond 120. I don't ride when it gets that hot. A 50 or 60 weight oil does not lube better than a 40 weight within the 114 degree temp range, and offers no benefit to me. I run a 10w-40 because it's all I need (I'd rather run a 20w-40), a lighter oil circulates better, drains back faster, and flows through the oil filter better.

Second, multigrade oils are made by taking a light base stock and adding "long chain" molecules to it. These expand as they are heated and impede the oil from flowing with the result that the oil will not thin out as much as the unmodified base stock would have. These long molecules are not very good lubricants in their own right, and are comparatively easy to break apart, especially under the kind of shear stresses applied by a transmission or gear drives. The greater the difference is between the upper and lower viscosity values, the greater the ratio of the long chain molecules to "normal", better lubricating short molecules has to be, and the more quickly the oil's viscosity will break down, all other things being equal. A 20w-40 has a two to one viscosity ratio, a 15w-50 has a 3.3:1 ratio, and a 10w-40 is at 4:1. The Motorex, at 10w-60 is all the way out to 6:1, so it would seem that it should be more subject to viscosity loss than oils with a lower viscosity ratio, at least if that's all there was to it. But, of course oil is a very complicated compound these days, and I am not a chemist.

The third thing is that I can get an oil that meets all of my standards for less money. Even though I make a point not to cut corners on things like lubrication, I am kind of cheap. :cry:

Things to look for on the bottle would be an API grade of SG or SH, a JASO grade of MA, or an API Commercial grade (CF or higher). All of these are good. Don't use a JASO MB oil in a situation where your clutch will be exposed to it, and be wary of "energy conserving" oils, as your clutch may not like them either.

Once you get by all that stuff, the truth is that which oil you use is less important than how well you maintain it.

:cry:

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  • 642MX

Posted January 11, 2005 - 05:20 PM

#3

I've never used the 10W60, but I do use the 10W50 motorex.

  • inte

Posted January 11, 2005 - 05:51 PM

#4

I would not use this oil on 3 counts, mainly 2. One is that it's heavier than I need to have. A 10w-40, or 20w-40 is good for everything up to 114 degrees F. A ?w-50 is OK to somewhere beyond 120. I don't ride when it gets that hot. A 50 or 60 weight oil does not lube better than a 40 weight within the 114 degree temp range, and offers no benefit to me. I run a 10w-40 because it's all I need (I'd rather run a 20w-40), a lighter oil circulates better, drains back faster, and flows through the oil filter better.

Second, multigrade oils are made by taking a light base stock and adding "long chain" molecules to it. These expand as they are heated and impede the oil from flowing with the result that the oil will not thin out as much as the unmodified base stock would have. These long molecules are not very good lubricants in their own right, and are comparatively easy to break apart, especially under the kind of shear stresses applied by a transmission or gear drives. The greater the difference is between the upper and lower viscosity values, the greater the ratio of the long chain molecules to "normal", better lubricating short molecules has to be, and the more quickly the oil's viscosity will break down, all other things being equal. A 20w-40 has a two to one viscosity ratio, a 15w-50 has a 3.3:1 ratio, and a 10w-40 is at 4:1. The Motorex, at 10w-60 is all the way out to 6:1, so it would seem that it should be more subject to viscosity loss than oils with a lower viscosity ratio, at least if that's all there was to it. But, of course oil is a very complicated compound these days, and I am not a chemist.

The third thing is that I can get an oil that meets all of my standards for less money. Even though I make a point not to cut corners on things like lubrication, I am kind of cheap. :cry:

Things to look for on the bottle would be an API grade of SG or SH, a JASO grade of MA, or an API Commercial grade (CF or higher). All of these are good. Don't use a JASO MB oil in a situation where your clutch will be exposed to it, and be wary of "energy conserving" oils, as your clutch may not like them either.

Once you get by all that stuff, the truth is that which oil you use is less important than how well you maintain it.

:cry:


Now this brings back memories of an article I read a couple years ago in a Cycle World on motorcycle-specific oils. The article brought up several of the "finer" points you mentioned, all valid, and their conclusion was pretty much the last thing you said - maintenance is more crucial than the choice of oil.

I don't like to cut corners either & that's the main reason I'm asking - I have an endorsement from Motorex & use the stuff in my KTM & Gas Gas bikes - there's a few gallons of the 10w-60 in the garage. I'm thinking I'll run a couple changes of that & order some of the 10w-50 - I change the oil every 3 rides or so ...

I've also heard a couple people mention it's more important to choose a particular brand & stick with it. Something about the additives & such forming coatings that shouldn't be disturbed. Changing viscosities is fine (as weather/location merits), but it's best to always use the same brand...

I'm sure if you got two people together to discuss this you'd have at least 3 opinions...

  • grayracer513

Posted January 11, 2005 - 07:57 PM

#5

I've also heard a couple people mention it's more important to choose a particular brand & stick with it. Something about the additives & such forming coatings that shouldn't be disturbed. Changing viscosities is fine (as weather/location merits), but it's best to always use the same brand...

I'm sure if you got a couple people together to discuss this you'd have at least 3 opinions...

I don't know about coatings or other deposits. Most oil producers use much of the same chemistry in their blends. Just the proportions vary, with some things added, some things out. I change oil and clean the filter every 3 ride days, or every race day. I've got my son's 250F apart right now, and there isn't anything coating any part of that engine, outside of the combustion chamber, except clean oil. It sounds a bit like urban legend, I'd say.

3 opinions at least! :cry:





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