Mixing Rotella T4 and T6

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T4 is 15w40 "conventional" and T6 is 5w40 synthetic. I've been using T4 for a while without any problems except hard starting at lower ambient temps. I've used T6 before and the starts are good but shifts are quite notchy. My idea is to blend T4 and T6 50/50 to get a 10w40 that is really stout and really affordable... looking for a middle ground I guess. Your thoughts?
 
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I've used both. They are certainly cheap. I don't care for either, as shift quality quickly degrades compared to other, better performing oils.
 
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Festus, MO
Best answer is to try it for an OCI and see how it holds up and how the shifting feels. Can't see how it could possibly hurt.
 
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Originally Posted by DGXR
T4 is 15w40 "conventional" and T6 is 5w40 synthetic. I've been using T4 for a while without any problems except hard starting at lower ambient temps. I've used T6 before and the starts are good but shifts are quite notchy. My idea is to blend T4 and T6 50/50 to get a 10w40 that is really stout and really affordable... looking for a middle ground I guess. Your thoughts?
Thats an OK plan but.. Mobil 1 15w50 is $23/5qts. $4.60/qt T6 5w40- is $21/4qts T4 15w40 is $14/4qts Blend them and you come up to $4.40/qt You said you wanted really stout and really affordable... i think the Mobil1 is the middle ground fair deal?
 
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A few questions here in the middle of the summer... What bike are you riding? Air-cooled, liquid-cooled, V-Twin, four-cylinder, etc What ambient temperature are you starting the motorcycle at that 15w40 is causing hard starting? Looks like you are in California. As in the bike won't start and experiences difficulty to get going at all? With that said T5 is still a 15w40, despite the creative math. smile
 
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I mix the same 2 oils for my Yamaha Roadliner. Air cooled 1800cc. Same reasons you gave, I started using the 5w40 and noticed the shift issues at about 2000 miles, went to the Mobil 15w50 and come Oct the morning starts would be slow so I started blending the T4 and T6 and its been fine for the last 15000 miles. I dont know what it will be like when my stash of the old Rotella is gone and I have to buy the new stuff.
 
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Mixing synthetic uniform molecules with conventional random size molecule just makes less desirable synthetic... but it does improve the conventional... [Linked Image] [Linked Image]
 
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I have done exactly this and someone here wagged their finger in my face and was like "nooooooooo it doesn't work like that". It works fine.
 
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Colorado, USA
It'll work fine, agreed. I judge shift quality falling off as the determinant for oil changes, if I haven't reached the 5,000 mile mark. Haven't had a problem with shift quality falling off before 5,000 miles in the past 3 years now that I've been using either of the Mobil 1 motorcycle specific oils. That stuff is just plain good in 10w40 4T or 20w50 V-Twin flavor in the shared sump of the Kawasaki ZRX 1200. I get it guys want to save a few bucks, then they change oil at half the recommended interval of most manufacturers or even more frequently than that. Running 3.3 quarts of either oil mentioned above for 5,000 miles with a filter is the best deal going when you consider the cost of the partial quart and not having to recycle double the amount of motor oil if changing it at 2,000 or 2,500 miles.
 

CT8

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Originally Posted by BusyLittleShop
Mixing synthetic uniform molecules with conventional random size molecule just makes less desirable synthetic... but it does improve the conventional... [Linked Image] [Linked Image]
Hydroisomerized oils?
 
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Wisconsin
When it comes to mixing my thought is, are both suitable oils by themselves? If that is the case, no worries. Of course you need to be in the ballpark for the correct viscosity and all. I mix, within reason.
 
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There is also a T6 15w40 FS version that you could try without mixing. I've found that by switching over to a FS or even a blended oil that it makes a huge difference when the temps drop even using the same grade of oil. If it still ends up being too thick you can always mix in some 5w40. At Walmart for motorcycle specific oil's in 10w40 & 20w50 there is Castrol Actevo that's available for $6.32 qt, Valvoline FS for $7.37 qt but then there's also Super Tech FS @ $8.68 qt which doesn't make sense as it's actually more expensive than the other options available.
 
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Originally Posted by BusyLittleShop
Mixing synthetic uniform molecules with conventional random size molecule just makes less desirable synthetic... but it does improve the conventional...
It is an amazing marvel of engineering how they get the synthetic molecules of the numerous base oils with all different molecular structures and sizes, the viscosity modifiers, the anti-wear/extreme pressure, anti-corrosive, and antioxidant additives, friction modifiers, defoamers, dispersants, and detergents all the exact same molecular size and shape isn't it? whistle
 
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Quote below from his first post that started the thread. He hasn't checked back in with a response to questions that have been asked or indicating he's seen the input. So at this point we are somewhat throwing out additional information that we don't know is even desirable to his quest. "I've been using T4 for a while without any problems except hard starting at lower ambient temps. I've used T6 before and the starts are good but shifts are quite notchy. My idea is to blend T4 and T6 50/50 to get a 10w40 that is really stout and really affordable". I take that to mean he doesn't want a 15w40. At any sane temperature he's going to be starting that motorcycle T4 or T5 are going to crank the same. Not until colder temperatures none of us would ride a motorcycle in would the semi-synthetic T5 possibly have an advantage. With that said, he lives in California, it's the middle of summer, and still not sure what bike is hard starting on cooler mornings with 15w40. I suspect it's not a V-Twin as there isn't one out there that specifies a 5w40 like he has indicated using that I'm aware of.
 
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Originally Posted by MotoTribologist
It is an amazing marvel of engineering how they get the synthetic molecules of the numerous base oils with all different molecular structures and sizes, the viscosity modifiers, the anti-wear/extreme pressure, anti-corrosive, and antioxidant additives, friction modifiers, defoamers, dispersants, and detergents all the exact same molecular size and shape isn't it?
It is amazing engineering... whether base or additive... synthetics are purified and uniform... Quote Mobil 1 "Synthetic oil is not only refined but also distilled, purified and broken down into its basic molecules. This process not only removes more impurities from the crude oil, but also enables individual molecules in the oil to be tailored to the demands of modern engines. These customized molecules provide higher levels of protection and performance than conventional oils." Quote Amsoil "Pure, Uniform Molecules Form Strong, Stable Lubricants Petroleum oils have molecular structures that are randomly organized and, consequently, have limited performance abilities. Their varied and inconsistent molecular structure results in less film strength and lubricity. Their paraffinic wax content also makes them more susceptible to viscosity variance and cold-temperature flow problems."
 
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127
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WI
Originally Posted by Smoky14
Just got to ask, why not just use T5 and save all the messing around? Smoky PS: I've had great success running T5
Their is no industry standards for the amount of synthetic in syn blend/partial syn oils. A 50/50 mix of T4 and T6 likely has quite a bit higher syn content than T5.
 
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