how should density be evaluated for engine oils?
how much deviation is allowable from fresh oil limits.
Original Post
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Not a good indicator of anything
oils vary in density depending on vis and additives etc.
As far as trending used oil for a falure mode most all other tests are better such as
VIS
metals
TBN
TAN etc
oils vary in density depending on vis and additives etc.
As far as trending used oil for a falure mode most all other tests are better such as
VIS
metals
TBN
TAN etc
Hardy,
Density will not change too much unless there is an external contamination from another fluid.
Perhaps you meant viscosity changes, not density. Viscosity changes of 10% are possible without being considered a reason for an oil change
Changes over 10% should be investigated, and a change in viscosity of more than 20% requires action, i.e. oil change.
With the TBN as another indicator there are also limits such as: TBN change more than +/- 0.5%=attention, more than +/- 1%=action.
Density will not change too much unless there is an external contamination from another fluid.
Perhaps you meant viscosity changes, not density. Viscosity changes of 10% are possible without being considered a reason for an oil change
Changes over 10% should be investigated, and a change in viscosity of more than 20% requires action, i.e. oil change.
With the TBN as another indicator there are also limits such as: TBN change more than +/- 0.5%=attention, more than +/- 1%=action.
Density is not generally a parameter for oil condition monitoring, but will vary with additive concentration particularly with marine engine oils which can have TBN up to 70 to 100
Normal high speed diesel engine oil will have density of around 0.89 wheras 70 TBN is up to 0.93gm/cc
Most lube HVI oils are around 0.88gm/cc
Note Naphthenic oils have a higher density.
Density rises with inceasing viscosity
Normal high speed diesel engine oil will have density of around 0.89 wheras 70 TBN is up to 0.93gm/cc
Most lube HVI oils are around 0.88gm/cc
Note Naphthenic oils have a higher density.
Density rises with inceasing viscosity
