Full synthetic oil for more mileage. .

Just done 78 000km on my dct, thinking of introducing full synthetic , now factory specify 10w 30 but I see Yamaha use 10w 50 on my mt09 tracer which factory also states round 10w 30. Is this because full synthetic is a bit thinner? Anybody have a clear answer to this..?

Before my venture into the practice of law, I worked as a chemical engineer/business manager for a chemical company where one of my assignments was to market viscosity index improvers for motor oils. I learned this area well.  In a nutshell, a straight grade SAE 10W motor oil and a multi grade 10W - xx oil has the same viscosity (resistance to flow) characteristics at low temperatures.  The difference is that the multigrade oil had polymer dispersed in to  which opens up as the temperature rises.  Think of it like this, " make a fist with your hand this is what the polymer is like when the oil is cold.  Then open up your hand as wide as you can this is what the polymer looks like when oil gets hot.  Contrary to popular belief the oil does not thicken but instead it does not thin out as much was an oil without polymer.  The second number of a multigrade oil is the relative measure of how much the oil resists thinning.  Thus, a straight 10W grade oil and a 10W-30 will have the same characteristics when the oil is cold and sitting in the sump of your engine.  After the engine comes up to temperature, the straight 10 oil will be very thin and have little resistant to flow whereas the 10W-30 oil will still be thinner than either of the cold oils but will be "thicker" (more resistant to flow) than the straight 10 oil because the polymer will have expanded. The 10W-50 is just like the straight 10 oil and the 10W - 30 at cold temperatures (they have the same viscosity) but it contains extra polymer than the 10-30 so that at high temp it will not lose as much as its initial viscosity. 

The trade off is the extra polymer in the 10W-50 does two other things that can be detrimental. First it shears down (polymer chains physically break apart) because of the shearing/friction between the tight clearances - i.e.  the film between the piston and cylinder. So eventually that 10W-50 oil might look like a 10-30 oil after a thousand miles or so. The 10W-30 will not change as much because there is less polymer to breakdown. The polymer breakdown can leave carbon-like deposits.  Synthetics tend to be better because the synthetic base oil (before polymers and other additives) is more stable than conventional mineral oil.  The engine manufacturers design and test their engine's oiling systems passages and clearances etc.. with a particular grade oil in mind.  If you follow the manufacturer's guidelines you will not go wrong.  In the VFR 1200 it calls for 10W-30 not a 10W-50.  I use Mobile 1 10W-30 synthetic automobile oil.  Before anyone responds about clutch slippage, I do not use the energy conserving "EC" version exclusively - it a higher level of molybdenum additives which are implicated in clutch slippage.  I use a 2:1 combination (or solely) the Mobile 1 high mileage 10W-30 and the regular EC version.  It works great, is and much less expensive than MC only oil and is widely available. 

Yeah. Stick to the manufacturer's recommended viscosity for the typical temperatures in your area. 

And brand name is basically your only guarantee of quality. 

You can get your used motor oil analysed at regular intervals to know how it performs but it's a hassle and a cost. Anything else is just superstition. 

8 hours ago, JED13

Before anyone responds about clutch slippage,

How about the typical motorcycle gearbox which is integral to the engine ?

Does that not require specific additives not present in car engine oils ?

18 hours ago, JED13

Before my venture into the practice of law, I worked as a chemical engineer/business manager for a chemical company where one of my assignments was to market viscosity index improvers for motor oils. I learned this area well.  In a nutshell, a straight grade SAE 10W motor oil and a multi grade 10W - xx oil has the same viscosity (resistance to flow) characteristics at low temperatures.  The difference is that the multigrade oil had polymer dispersed in to  which opens up as the temperature rises.  Think of it like this, " make a fist with your hand this is what the polymer is like when the oil is cold.  Then open up your hand as wide as you can this is what the polymer looks like when oil gets hot.  Contrary to popular belief the oil does not thicken but instead it does not thin out as much was an oil without polymer.  The second number of a multigrade oil is the relative measure of how much the oil resists thinning.  Thus, a straight 10W grade oil and a 10W-30 will have the same characteristics when the oil is cold and sitting in the sump of your engine.  After the engine comes up to temperature, the straight 10 oil will be very thin and have little resistant to flow whereas the 10W-30 oil will still be thinner than either of the cold oils but will be "thicker" (more resistant to flow) than the straight 10 oil because the polymer will have expanded. The 10W-50 is just like the straight 10 oil and the 10W - 30 at cold temperatures (they have the same viscosity) but it contains extra polymer than the 10-30 so that at high temp it will not lose as much as its initial viscosity. 

The trade off is the extra polymer in the 10W-50 does two other things that can be detrimental. First it shears down (polymer chains physically break apart) because of the shearing/friction between the tight clearances - i.e.  the film between the piston and cylinder. So eventually that 10W-50 oil might look like a 10-30 oil after a thousand miles or so. The 10W-30 will not change as much because there is less polymer to breakdown. The polymer breakdown can leave carbon-like deposits.  Synthetics tend to be better because the synthetic base oil (before polymers and other additives) is more stable than conventional mineral oil.  The engine manufacturers design and test their engine's oiling systems passages and clearances etc.. with a particular grade oil in mind.  If you follow the manufacturer's guidelines you will not go wrong.  In the VFR 1200 it calls for 10W-30 not a 10W-50.  I use Mobile 1 10W-30 synthetic automobile oil.  Before anyone responds about clutch slippage, I do not use the energy conserving "EC" version exclusively - it a higher level of molybdenum additives which are implicated in clutch slippage.  I use a 2:1 combination (or solely) the Mobile 1 high mileage 10W-30 and the regular EC version.  It works great, is and much less expensive than MC only oil and is widely available. 

Cool thanks for taking the time to answer.. really appreciate, will do the Yamaha lube full synth 10w -30 next change

Silvo, 6/2/2017 at 1:31 PM

answer to this..?

``Good questions!  Unfortunately transmission oils were not in my sphere, but i know just enough to give a general answer.  Transmission oils have changed over the years to provide less drag (higher fuel efficiency) and to become more compatible with engine operation. Motorcycle oils have changed in formulation to become very similar to automobile engines because of the implementation of emissions/catalytic converters. Chemistry-wise the additive packages (detergents, VI improvers, friction modifiers, dispersants, etc...) have changed to be more automotive-like.  

To make sure, at least in my mind, that the auto versions of Mobile 1 were safe for my motorcycles, I pulled the MSD sheets of 3 versions of the 10W-30 automobile oils and the 10W-40 MC oil I compared the minerals and physical characteristics and the Mobile 1 10W-30 auto oils were fine.  I just would not use the energy conserving oil because it has more moly, which can cause clutch slippage.  I did the same for my V-Strom  and used it for many They treat my engines very well.