Hey Gary, I openly admit that I'm one of these:
Base Oil Viscosity Discussion Thread
- Thread starter TallPaul
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My last goof ball blend:
2.5 qts Durablend 20w50
2 qts Valvoline 20w
1 qt can't remember, but was leftovers
1 pint VSOT
half pint CD2 75000 mile oil treatment
No, I didn't use Bruces PCMO add in this blend, am saving for motorhome to boost zddp in the Maxlife Synthetic.
2.5 qts Durablend 20w50
2 qts Valvoline 20w
1 qt can't remember, but was leftovers
1 pint VSOT
half pint CD2 75000 mile oil treatment
No, I didn't use Bruces PCMO add in this blend, am saving for motorhome to boost zddp in the Maxlife Synthetic.
TallPaul, now that sounds like some of the blends that my mower gets, as I always seem to have 1/4 quart of this, 1/2 quart of that. I just pour 'em all into one bottle, shaken, not stirred, and dump away. I figure that as little oil that the mower holds, vs. I change it every 20 hours or so (which with my lawn is at least 3 times a season), what's the harm, as it isn't in there long enough to do any major addtive clashing anyway.
Saving the PCMO Bruce blend, tisk tisk..
!
Saving the PCMO Bruce blend, tisk tisk..
Originally Posted By: Drivebelt
Quote:
5w20 is 3.9 cSt
5w30 is 4.1 cSt
10w30 is 6.0 cSt
SAE 30 is 9.3 cSt
10w40 is 5.5 cSt
15w40 is 7.0 cSt
and 20w50 is 10.2 cSt
Those 5W numbers don't seem correct.
If you look at Chevron's base oil page, they have a table where it states that a 5w-20/5W-30 (GF-4) can be blended with 5R and 220R …
5R ……4.7 cSt
220R …6.4
Given the viscosity of those 2 base oils, there is no way to blend the base oils lower than 4.7 cSt (100% 5R = 4.7) -- so I don’t see how the 5W's can be around 4.0 cSt.
FWIW … when I researched the issue of base oil use in motor oils a few months ago, although it was pretty hard to come up with some concrete numbers, I arrived at the following …
5W-20 … 4.9 cSt
5W-30 … 5.1 cSt
10W-30 … 5.6 - 5.8 cSt
15W-40 …~ 7.0 cSt
These would be for Group II base oils. If blending with Group III or PAO, the viscosity of the base oils would be higher because they have better cold flow properties.
Now I see why 5w-20, 5w-30 viscosity are so close. If VII thickins oil at all temps, wouldn't one that uses less perform best in winter? Are 5w-20 and 10w-30 each better than 5w-30?
Quote:
5w20 is 3.9 cSt
5w30 is 4.1 cSt
10w30 is 6.0 cSt
SAE 30 is 9.3 cSt
10w40 is 5.5 cSt
15w40 is 7.0 cSt
and 20w50 is 10.2 cSt
Those 5W numbers don't seem correct.
If you look at Chevron's base oil page, they have a table where it states that a 5w-20/5W-30 (GF-4) can be blended with 5R and 220R …
5R ……4.7 cSt
220R …6.4
Given the viscosity of those 2 base oils, there is no way to blend the base oils lower than 4.7 cSt (100% 5R = 4.7) -- so I don’t see how the 5W's can be around 4.0 cSt.
FWIW … when I researched the issue of base oil use in motor oils a few months ago, although it was pretty hard to come up with some concrete numbers, I arrived at the following …
5W-20 … 4.9 cSt
5W-30 … 5.1 cSt
10W-30 … 5.6 - 5.8 cSt
15W-40 …~ 7.0 cSt
These would be for Group II base oils. If blending with Group III or PAO, the viscosity of the base oils would be higher because they have better cold flow properties.
Now I see why 5w-20, 5w-30 viscosity are so close. If VII thickins oil at all temps, wouldn't one that uses less perform best in winter? Are 5w-20 and 10w-30 each better than 5w-30?
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