Reclaiming fuel contaminated oil

two samples...same pil

one with fuel dilution

one without

krl test........

which one shears more?
It depends on shear forces and specific circumstances. Most engines do not tend to shear the VM.

But also in general the presence of fuel is detrimental to the VII in the oil. Use an oil with no VM and there won’t be any shear regardless of fuel.
 
It depends on shear forces and specific circumstances. Most engines do not tend to shear the VM.

But also in general the presence of fuel is detrimental to the VII in the oil. Use an oil with no VM and there won’t be any shear regardless of fuel.
what is VM?
 
So if there is no VM, then fuel has no effect on shear stability?

Do most common off the shelf brands use VMs?

Which do not?
No, there is nothing to shear. Oil molecules will not shear in an engine, the shear forces are nowhere near great enough to do this.

As noted, nearly all oils use VII except monogrades and a couple muti-grade oils that could also be labeled as a monograde. But the shear stability is dependent on the quality of the VII as well as the tendency of a specific engine to cause shear.
 
No, there is nothing to shear. Oil molecules will not shear in an engine, the shear forces are nowhere near great enough to do this.

As noted, nearly all oils use VII except monogrades and a couple muti-grade oils that could also be labeled as a monograde. But the shear stability is dependent on the quality of the VII as well as the tendency of a specific engine to cause shear.
As normal, I am misunderstanding something. Please help me understand.

If a motor oil starts off at viscX, and ends at viscX-1......that is due to viscosity modifiers "losing a battle"

If in an engine oil does not make oil shear, then what causes the viscosity to change?

Is it the fuel "attacking" the VMs and not the "oil"?????
 
As normal, I am misunderstanding something. Please help me understand.

If a motor oil starts off at viscX, and ends at viscX-1......that is due to viscosity modifiers "losing a battle"

If in an engine oil does not make oil shear, then what causes the viscosity to change?

Is it the fuel "attacking" the VMs and not the "oil"?????
Fuel dilution is essentially a lower viscosity fluid being mixed with one of a higher viscosity. If there is fuel in the oil then it will lower the viscosity of the oil just by being there regardless of whether it is a monograde oil with no VII or a multi-grade.

VII degradation is a separate issue. Fuel does attack the polymer molecule and can cause both temporary and permanent damage just by itself. Look it up, there are lots of sources on this.

The other way VII is degraded is by mechanical shearing of the VII molecule. This can be exacerbated by the presence of fuel.

 
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