I suppose you could dump a pint or quart in per oil change and not hurt anything. The HDEO would boost your additives just a hair. OTOH I tend to agree with graphite.....
mixing oils
- Thread starter RogerBacon
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What's the consensus or opinions on mixing related oils of the same weights, such as a couple of quarts of Quaker State conventional, a qt. of Quaker State Horsepower, and a qt. of Pennzoil Platinum? Any problems with additives' clash?
Originally Posted By: RogerBacon
OK here is the deal-- I can get 15w40 diesel oil for free. I want to mix it with something I buy to make it usable it a 2002 Bonneville. I think the 15w40 is too heavy for use in the cold weather in Ontario. Any suggestions would be appreciated. Thanks Roger
For winter in Ontario, you might want to avoid using the 15w40 and use a 0W-30.
But after winter, that 15w40 will be fine. Consider the following.
The oils to be mixed:
Code:
TYPICAL 15w40
40°C kinematic viscosity 120 cSt
100°C kinematic viscosity 15 cSt
TYPICAL 5W-20
40°C kinematic viscosity 50 cSt
100°C kinematic viscosity 8.5 cSt
Mix 2 parts 15w40 and 3 parts 5W-20, and the estimate of what you'll get is
Code:
40°C kinematic viscosity 70 cSt
100°C kinematic viscosity 10.5 cSt
That result would be a typical North American xW-30. We don't know what the low-temperature behavior is, but its probably going to be like a 10W.
To use even more of your free 15w40 oil, how about a 1:1 mix:
Code:
40°C kinematic viscosity 76 cSt
100°C kinematic viscosity 11 cSt
or 3 parts 15w40, 2 parts 5W-20
Code:
40°C kinematic viscosity 83 cSt
100°C kinematic viscosity 11.8 cSt
or 2 parts 15w40, 1 parts 5W-20
Code:
40°C kinematic viscosity 88 cSt
100°C kinematic viscosity 12.3 cSt
All of those mixes fall into the xW-30 range. Note that they are getting progressively thicker.
For comparison, the 5w30 oils that GM specifies for the 3800 engines is 10.5–11.0 cSt at 100°C. You should be able to go thicker, though.
OK here is the deal-- I can get 15w40 diesel oil for free. I want to mix it with something I buy to make it usable it a 2002 Bonneville. I think the 15w40 is too heavy for use in the cold weather in Ontario. Any suggestions would be appreciated. Thanks Roger
For winter in Ontario, you might want to avoid using the 15w40 and use a 0W-30.
But after winter, that 15w40 will be fine. Consider the following.
The oils to be mixed:
Code:
TYPICAL 15w40
40°C kinematic viscosity 120 cSt
100°C kinematic viscosity 15 cSt
TYPICAL 5W-20
40°C kinematic viscosity 50 cSt
100°C kinematic viscosity 8.5 cSt
Mix 2 parts 15w40 and 3 parts 5W-20, and the estimate of what you'll get is
Code:
40°C kinematic viscosity 70 cSt
100°C kinematic viscosity 10.5 cSt
That result would be a typical North American xW-30. We don't know what the low-temperature behavior is, but its probably going to be like a 10W.
To use even more of your free 15w40 oil, how about a 1:1 mix:
Code:
40°C kinematic viscosity 76 cSt
100°C kinematic viscosity 11 cSt
or 3 parts 15w40, 2 parts 5W-20
Code:
40°C kinematic viscosity 83 cSt
100°C kinematic viscosity 11.8 cSt
or 2 parts 15w40, 1 parts 5W-20
Code:
40°C kinematic viscosity 88 cSt
100°C kinematic viscosity 12.3 cSt
All of those mixes fall into the xW-30 range. Note that they are getting progressively thicker.
For comparison, the 5w30 oils that GM specifies for the 3800 engines is 10.5–11.0 cSt at 100°C. You should be able to go thicker, though.
Stu---Thank you very much--that was a great answer. It helped very much. I will use the 1:1 ratio when the weather warms up a bit. Thanks again. Roger
Originally Posted By: ARCOgraphite
I would just run the JDM idemitsu Toyota or Honda 0w-20 if you want a winter blend. The voa formulation seems uneclipsed by anyone for a GF4. If wanting to thin the already thin 5w30, 300mL/4L at most seems to do it.
There is similar discussion over here:
https://bobistheoilguy.com/forums/posts/1685161/
And I quote CATERHAM:
Originally Posted By: CATERHAM
In fact you could do a blend of 4 litres of the Toyota oil and 1 litre of Mobil 1 0W-40 and wind up with a 0w30 that would be heavier Castrol Edge 5w30 at 100C but still lighter than most other 20wts at start-up due to the VI that would still be over 200.
I would just run the JDM idemitsu Toyota or Honda 0w-20 if you want a winter blend. The voa formulation seems uneclipsed by anyone for a GF4. If wanting to thin the already thin 5w30, 300mL/4L at most seems to do it.
There is similar discussion over here:
https://bobistheoilguy.com/forums/posts/1685161/
And I quote CATERHAM:
Originally Posted By: CATERHAM
In fact you could do a blend of 4 litres of the Toyota oil and 1 litre of Mobil 1 0W-40 and wind up with a 0w30 that would be heavier Castrol Edge 5w30 at 100C but still lighter than most other 20wts at start-up due to the VI that would still be over 200.
IMO, Blending usually does not work - except on SA monogrades. The overall formulations on high VI oils are way to complex to even begin to understand, even for most Chem E's.
No problem (no abnormal noise, rough idling) for my own blending formula (GC + FS) for 3k miles...
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