Oils that don't shear out of grade, shared sump

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What multiviscostiy oils do you find aren't prone to shear out of grade in a shared sump street bike?

From browsing the UOAs I can only think of two. Maybe you know others? Or maybe you can link to UOAs that prove me wrong about mine.

The ones I found are Motul 7100 4t 10W40 and Mobil 1 Racing 4T 10W40

I only really looked at xW40 oils since that what my bikes get.

I've seen similar questions asked before, but don't remember seeing good answers.
 
I believe Redline oil do well in this area since they tend to use less VII in their products.

Also it's worth noting that shearing isn't usually detrimental to wear until it gets really had, which is probably why the manufacturer specified a 40 grade oil in the first place to have viscosity reserve.
 
I have good experience with Motul 300V Factory Line, I find it resist fuel dilution and shearing better than 7100. For daily use, a lot of people cheaper suggest HDEO(diesel lubricant) to resist shearing on shared sump. Personally I still prefer gas lubricant because it seems offer better slipperiness compared to HDEO that may be useful for small engine performance.
 
I've got Motul 7100 in my Can Am, which shears like crazy, but need to get another 3-400 miles on it to reach the 4K mark before sending a sample in for lab testing. Its 4qts 10-40 and one qt 20-50. I've found that the 20-50 significantly reduces shearing and always use a qt to beef up what ever oil I'm testing. Without it, 3000miles is the limit, 4000 with the 20-50. WX being what it is, not likely to get the miles on for another month or two.
 
From what people post in the MC pages here, mineral oils have better resistance to shearing then synthetic oils. The brand of bike makes a difference as some are easier on oil then others. Like the Honda Goldwing is a shared sump bike, and doesn't beat up on the oil as much as a shared sump high revving sport bike.You don't say what bike you own but by your description I would guess a sport bike. Read thru the MC UOA section, to get an idea what works for other's with a similar type bikes and use pattern. One thing you'll see mentioned in some UOA'S from Blackstone labs is, a mention that someones oil has sheared a bit, but they don't think it will cause any harm and still recommend running the oil for a bit more.,,,
 
If you keep the OCI mileage down enough, almost any xW-40 oil will remain in grade. But if you take the oil to or past the mfg's recommended OCI, many oils will shear out of grade.

Motul 300V has worked very well for me and showed little if any shear in my UOA's. But any of the ester Group V oils (Redline MC, Belray EXS, Silkolene Pro S, Maxima Ultra or Maximum) should give similar results because they all have a high enough base oil viscosity index that they don't need to use viscosity index improvers to achieve their viscosity spread.

All oils, including esters, will lose viscosity from fuel dilution. That viscosity loss remains even after the fuel has evaporated out of the oil from usage.

I agree with the continued protection the viscosity reserve a SAE 40 weight oil gives even after shearing to an SAE 30 grade.

The most misunderstood concept here is that retaining viscosity does not necessarily equal good shifting quality in a shared sump bike. The friction quality of the oil is best predictor of shifting quality, and (as far as I've observed) none of the used oil analysis labs include that test for motorcycle oil. The oil industry has several ASTM tests which are used to demonstrate virgin oil products qualify for JASO MA, MA-1, MA-2, or MB, but who is supplying a measurement of that level of retention in used oil?
 
All oils will shear in a shared sump bike, just depends on the length of the run. Motul 7100 is kind of hard to find, I'd go with something more available. Mobil 1 Racing 4T is a good choice if the manual for your motorcycle blesses a 10W40 for your climate.
 
Shear this: this is really what we are all looking for in that bottle of oil at your favorite oil stop. Here is a ton of info that is more then you need to know. Now for all those mathematicians in the group, knock yourself out,,,,me , I just want things to slip and slide and get me to points unknown each day,,,,life is short, don't sweat the math...imho

https://en.wikipedia.org/wiki/Viscosity and more...
 
Oops. I was thinking of Motul 300V, not 7100. Thanks for correcting that!

If the OIC is short enough sure the oil won't shear out of grade. But typical oils seems to be out of grade by 2000-2500 miles in typical shared sump street bikes, while factory recommended OCIs are often 7500 miles or more. I get that it's probably OK to run the oil out of grade for a bit, but going to 7500 miles on oil that was out of grade at 2000 seems questionable to me.
 
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Depends...for my bike it recommends 10w40 or 10w50...no temperature ranges are given and many people in Europe especially run the 10w40 in their Triumphs year round. While I would worry about a 10w40 shearing too much for the full 6k mile OCI, I would be less so for the 10w50 which will probably end up in the 40 range where a 10w40 might end up as a thin 30 weight when at full operating temps.

Either way...best to do a few UOA at various OCI's to see when your fav oil is truly spent in your bike. For me I usually just dump at the 4k mile mark on the high end just because my left foot tells me its time.
 
Don't fear the shear... because the difference in viscosity between
the grades is only 3 cSt and thats not 3 cSt thinner or thicker... the
measurement is 3 cSt in more flow... 3 cSt in more flow doesn't risk
increase wear... our modern engines protected by modern oils don't
operate with in a narrow 3 cSt range of risk...
 
Originally Posted By: BusyLittleShop
Don't fear the shear... because the difference in viscosity between
the grades is only 3 cSt and thats not 3 cSt thinner or thicker... the
measurement is 3 cSt in more flow... 3 cSt in more flow doesn't risk
increase wear... our modern engines protected by modern oils don't
operate with in a narrow 3 cSt range of risk...



Heard it more than once....still don't believe it since out of grade 5w40 has set off Triumph oil lights at a hot idle.
 
Originally Posted By: Robenstein
Run a straight 10 weight oil in a small block chevy that normally would run on a 30 weight and see how long it lives.


No ones talking about anything that extreme, the conversation is a 40 grade that shears into a 30 grade.
 
I used Rotella 15/40 in my old R6, '04 Goldwing and my ST1100. Love that oil, cheap, good and easy to find. My son uses it in his VT1100-T and Ninja 650.
I use to track my R6 so I would change the oil out every two track days, not many miles but they were hard miles.

ROD
 
Originally Posted By: 901Memphis
Originally Posted By: Robenstein
Run a straight 10 weight oil in a small block chevy that normally would run on a 30 weight and see how long it lives.


No ones talking about anything that extreme, the conversation is a 40 grade that shears into a 30 grade.

Not exactly. We discussed continuing to use oil for another 5500 miles after it had sheared out of grade. I might have seen a UOA where oil has sheared down 2 grades. I know I've seen it come very close. Anyway I wasn't assuming the 40 will be a 30 (rather than 20) after the end of a 7500 mile OCI.
 
I use 10-30 Amsoil Motorcycle oil in all my bikes. They are 30wt when I drain them according to the UOA report. I like the few extra HP of the 30wt over the 40wt. My collection of Honda's mostly have 0.0009"-0.0022" main bearing clearances. That certainly does not dictate a 40wt. Oil. If this were a Honda Civic we'd all be using 0-20wt oil and not giving it a second thought.

Dave
 
Originally Posted By: Robenstein



Heard it more than once....still don't believe it since out of grade 5w40 has set off Triumph oil lights at a hot idle.



You still haven't mentioned what psi your Triumph oil light sets off...
 
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